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Braz. j. med. biol. res ; 53(2): e8616, 2020. graf
Article in English | LILACS | ID: biblio-1055497


Previous research has shown that suppression of miR-383 can prevent inflammation of the endothelium, as well as postpone the development of atherosclerosis. However, the role of miR-383 in endothelial cell apoptosis in diabetes remains unclear. The aim of this study was to investigate the function of miR-383 in high glucose-induced apoptosis and oxidative stress in endothelial cells. A series of experiments involving qualitative polymerase chain reaction, cell transfection, luciferase assay, assessment of cell death, detection of catalase and superoxide dismutase concentrations, detection of intracellular reactive oxygen species (ROS), and western blot analysis were performed in this study. We found that miR-383 expression was promoted, while NAD+-dependent deacetylase and sirtuin 1 (SIRT1) expressions were suppressed in the endothelium of the aorta in db/db mice as well as in human umbilical vein endothelial cells, which were treated with high glucose (HG). Increased expression of miR-383 decreased expression of SIRT1, while suppression of miR-383 promoted expression of SIRT1 in human umbilical vein endothelial cells (HUVECs). Furthermore, suppression of miR-383 following transfection with miR-383 suppressor repressed cell death and generation of ROS in HUVECs. SIRT1 knockdown by siRNA-SIRT1 reversed the suppressive effect of miR-383 inhibition on ROS production and cell apoptosis induced by HG treatment. Overall, the findings of our research suggested that suppression of miR-383 repressed oxidative stress and reinforced the activity of endothelial cells by upregulation of SIRT1 in db/db mice, and targeting miR-383 might be promising for effective treatment of diabetes.

Animals , Male , Rabbits , Endothelium, Vascular/drug effects , Apoptosis/drug effects , Oxidative Stress/drug effects , MicroRNAs/antagonists & inhibitors , Sirtuin 1/metabolism , Glucose/pharmacology , Endothelium, Vascular/cytology , Endothelium, Vascular/physiology , Signal Transduction , Cells, Cultured , Mice, Inbred C57BL
Arq. bras. cardiol ; 111(6): 772-781, Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-973811


Abstract Background: Cardiac remodeling is a specific response to exercise training and time exposure. We hypothesized that athletes engaging for long periods in high-intensity strength training show heart and/or vascular damage. Objective: To compare cardiac characteristics (structure and function) and vascular function (flow-mediated dilation [FMD] and peripheral vascular resistance [PVR]) in powerlifters and long-distance runners. Methods: We evaluated 40 high-performance athletes (powerlifters [PG], n = 16; runners [RG], n = 24) and assessed heart structure and function (echocardiography), systolic and diastolic blood pressure (SBP/DBP), FMD, PVR, maximum force (squat, bench press, and deadlift), and maximal oxygen uptake (spirometry). A Student's t Test for independent samples and Pearson's linear correlation were used (p < 0.05). Results: PG showed higher SBP/DBP (p < 0.001); greater interventricular septum thickness (p < 0.001), posterior wall thickness (p < 0.001) and LV mass (p < 0.001). After adjusting LV mass by body surface area (BSA), no difference was observed. As for diastolic function, LV diastolic volume, wave E, wave e', and E/e' ratio were similar for both groups. However, LA volume (p = 0.016) and BSA-adjusted LA volume were lower in PG (p < 0.001). Systolic function (end-systolic volume and ejection fraction), and FMD were similar in both groups. However, higher PVR in PG was observed (p = 0.014). We found a correlation between the main cardiovascular changes and total weight lifted in PG. Conclusions: Cardiovascular adaptations are dependent on training modality and the borderline structural cardiac changes are not accompanied by impaired function in powerlifters. However, a mild increase in blood pressure seems to be related to PVR rather than endothelial function.

Resumo Fundamento: Remodelamento cardíaco é uma resposta específica ao tempo e modalidade de treinamento. Nós hipotetizamos que atletas de treinamento de força de alta intensidade, por longo tempo, mostram dano à estrutura cardíaca e/ou vascular. Objetivo: Comparar as características cardíacas (estrutura e funcionalidade) e função vascular (dilatação fluxo-mediada, FMD e resistência vascular periférica, PVR) em powerlifters e corredores. Métodos: Nós avaliamos 40 atletas de alto-desempenho (powerlifters [PG], n = 16; corredores [RG], n = 24). Mensuramos estrutura e funcionalidade cardíaca (ecocardiografia), pressão arterial (SBP/DBP), FMD, PVR, força máxima (agachamento, supino e levantamento terra) e consumo máximo de oxigênio (ergoespirometria). Foi utilizado teste T de Student e correlação linear de Pearson (p < 0,05). Resultados: PG mostrou maior SBP/DBP (p < 0,001), espessura de septo interventricular (p < 0,001), parede posterior (p < 0,001) e massa do VE (p < 0,001); após ajuste pela superfície corporal (BSA), não houve diferença na massa do VE. O volume do VE, onda E, onda e', e a razão E/e' foram similares entre os grupos. O volume do AE (p = 0,016), mesmo ajustado pela BSA (p < 0,001) foi menor no PG. A função sistólica (volume sistólico final e fração de ejeção) e FMD foram similares nos grupos. Contudo, foi observada maior PVR no PG (p = 0,014). Houve uma correlação direta entre as alterações cardíacas e a carga total levantada no PG. Conclusões: As adaptações cardiovasculares são dependentes da modalidade e os valores encontrados na estrutura do coração não são acompanhados por prejuízo na funcionalidade. Entretanto, um leve aumento na pressão arterial pode estar associado com maior PVR e não com a função endotelial.

Humans , Male , Adolescent , Adult , Young Adult , Running/physiology , Endothelium, Vascular/physiology , Exercise/physiology , Athletes , Vascular Resistance/physiology , Blood Pressure/physiology , Brachial Artery/physiology , Echocardiography , Cross-Sectional Studies , Hypertrophy, Left Ventricular/diagnostic imaging , Dilatation , Exercise Test , Heart Rate/physiology , Hemodynamics/physiology
Arq. bras. cardiol ; 111(5): 699-707, Nov. 2018. tab, graf
Article in English | LILACS | ID: biblio-973784


Abstract Background: Heart failure with preserved ejection fraction (HFpEF) is a multifactorial syndrome characterized by a limited exercising capacity. High-intensity interval training (HIIT) is an emerging strategy for exercise rehabilitation in different settings. In patients with HFpEF, HIIT subacute effects on endothelial function and blood pressure are still unknown. Objective: To evaluate the subacute effect of one HIIT session on endothelial function and blood pressure in patients with HFpEF. Methods: Sixteen patients with HFpEF underwent a 36-minute session of HIIT on a treadmill, alternating four minutes of high-intensity intervals with three minutes of active recovery. Brachial artery diameter, flow-mediated dilation, and blood pressure were assessed immediately before and 30 minutes after the HIIT session. In all analyses, p <0.05 was considered statistically significant. Results: There was an increase in brachial artery diameter (pre-exercise: 3.96 ± 0.57 mm; post-exercise: 4.33 ± 0.69 mm; p < 0.01) and a decrease in systolic blood pressure (pre-exercise: 138 ± 21 mmHg; post-exercise: 125 ± 20 mmHg; p < 0.01). Flow-mediated dilation (pre-exercise: 5.91 ± 5.20%; post-exercise: 3.55 ± 6.59%; p = 0.162) and diastolic blood pressure (pre-exercise: 81 ± 11 mmHg; post-exercise: 77 ± 8 mmHg; p = 1.000) did not change significantly. There were no adverse events throughout the experiment. Conclusions: One single HIIT session promoted an increase in brachial artery diameter and reduction in systolic blood pressure, but it did not change flow-mediated dilation and diastolic blood pressure.

Resumo Fundamento: Insuficiência cardíaca com fração de ejeção preservada (ICFEP) é uma síndrome multifatorial caracterizada por limitação ao exercício. O treinamento intervalado de alta intensidade (HIIT) é uma estratégia emergente para a reabilitação do exercício em diferentes contextos. Em pacientes com ICFEP, os efeitos subagudos do HIIT sobre a função endotelial e a pressão arterial ainda são desconhecidos. Objetivo: Avaliar o efeito subagudo de uma única sessão do HIIT sobre a função endotelial e a pressão arterial em pacientes com ICFEP. Métodos: Dezesseis pacientes com ICFEP foram submetidos a uma sessão de 36 minutos de HIIT em esteira rolante, alternando quatro minutos de intervalos de alta intensidade com três minutos de recuperação ativa. O diâmetro da artéria braquial, a dilatação mediada pelo fluxo e a pressão arterial foram avaliados imediatamente antes e 30 minutos após a sessão de HIIT. Em todas as análises, p <0,05 foi considerado estatisticamente significativo. Resultados: Houve aumento do diâmetro da artéria braquial (pré-exercício: 3,96 ± 0,57 mm; pós-exercício: 4,33 ± 0,69 mm; p < 0,01), e diminuição da pressão arterial sistólica (pré-exercício: 138 ± 21 mmHg; pós-exercício: 125 ± 20 mmHg; p < 0,01). A dilatação mediada por fluxo (pré-exercício: 5,91 ± 5,20%; pós-exercício: 3,55 ± 6,59%; p = 0,162) e pressão arterial diastólica (pré-exercício: 81 ± 11 mmHg; pós-exercício: 77 ± 8 mmHg; p = 1,000) não se alteraram significativamente. Não houve eventos adversos durante o experimento. Conclusões: Uma única sessão do HIIT promoveu aumento do diâmetro da artéria braquial e redução da pressão arterial sistólica, mas não alterou a dilatação mediada pelo fluxo e a pressão arterial diastólica.

Humans , Male , Female , Middle Aged , Aged , Vasodilation/physiology , Blood Pressure/physiology , Endothelium, Vascular/physiology , High-Intensity Interval Training/methods , Heart Failure/physiopathology , Oxygen Consumption/physiology , Stroke Volume/physiology , Brachial Artery/physiology , Brachial Artery/diagnostic imaging , Endothelium, Vascular/diagnostic imaging , Echocardiography , Ultrasonography , Exercise Test/methods , Non-Randomized Controlled Trials as Topic , Heart Failure/diagnostic imaging
Acta cir. bras ; 33(11): 991-999, Nov. 2018. graf
Article in English | LILACS | ID: biblio-973476


Abstract Purpose: To determine whether the absence of transglutaminase 2 enzyme (TG2) in TG2 knockout mice (TG2-/-) protect them against early age-related functional and histological arterial changes. Methods: Pulse wave velocity (PWV) was measured using non-invasive Doppler and mean arterial pressure (MAP) was measured in awake mice using tail-cuff system. Thoracic aortas were excised for evaluation of endothelial dependent vasodilation (EDV) by wire myography, as well as histological analyses. Results: PWV and MAP were similar in TG2-/-mice to age-matched wild type (WT) control mice. Old WT mice exhibited a markedly attenuated EDV as compared to young WT animals. The TG2-/-young and old mice had enhanced EDV responses (p<0.01) as compared to WT mice. There was a significant increase in TG2 crosslinks by IHC in WT old group compared to Young, with no stain in the TG2-/-animals. Optical microscopy examination of Old WT mice aorta showed thinning and fragmentation of elastic laminae. Young WT mice, old and young TG2-/-mice presented regularly arranged and parallel elastic laminae of the tunica media. Conclusion: The genetic suppression of TG2 delays the age-induced endothelial dysfunction and histological modifications.

Animals , Male , Aorta, Thoracic/physiology , Aging/physiology , Endothelium, Vascular/physiology , Transglutaminases/physiology , GTP-Binding Proteins/physiology , Vasodilation/physiology , Immunohistochemistry , Age Factors , Mice, Knockout , Vascular Stiffness/physiology , Pulse Wave Analysis , Arterial Pressure/physiology
Arq. bras. cardiol ; 108(5): 436-442, May 2017. tab, graf
Article in English | LILACS | ID: biblio-838740


Abstract Background: Resistance exercise (RE) has been recommended for patients with cardiovascular diseases. Recently, a few studies have demonstrated that the intensity of a single bout of RE has an effect on endothelial adaptations to exercise. However, there is no data about the effects of different volumes of RE on endothelium function. Objective: The aim of the study was to evaluate the effects of different volumes of RE in a single bout on endothelium-dependent vasodilatation and nitric oxide (NO) synthesis in the mesenteric artery of healthy animals. Methods: Male Wistar rats were divided into three groups: Control (Ct); low-volume RE (LV, 5 sets x 10 repetitions) and high-volume RE (HV, 15 sets x 10 repetitions). The established intensity was 70% of the maximal repetition test. After the exercise protocol, rings of mesenteric artery were used for assessment of vascular reactivity, and other mesenteric arteries were prepared for detection of measure NO production by DAF-FM fluorescence. Insulin responsiveness on NO synthesis was evaluated by stimulating the vascular rings with insulin (10 nM). Results: The maximal relaxation response to insulin increased in the HV group only as compared with the Ct group. Moreover, the inhibition of nitric oxide synthesis (L-NAME) completely abolished the insulin-induced vasorelaxation in exercised rats. NO production showed a volume-dependent increase in the endothelial and smooth muscle layer. In endothelial layer, only Ct and LV groups showed a significant increase in NO synthesis when compared to their respective group under basal condition. On the other hand, in smooth muscle layer, NO fluorescence increased in all groups when compared to their respective group under basal condition. Conclusions: Our results suggest that a single bout of RE promotes vascular endothelium changes in a volume-dependent manner. The 15 sets x 10 repetitions exercise plan induced the greatest levels of NO synthesis.

Resumo Fundamentos: O exercício resistido (ER) tem sido recomendado para pacientes com doenças cardiovasculares. Recentemente, alguns estudos demonstraram que a intensidade de uma sessão de ER exerce um efeito sobre a disfunção endotelial. No entanto, não há dados sobre os efeitos de diferentes volumes de ER sobre a função endotelial. Objetivo: O objetivo deste estudo foi avaliar os efeitos de diferentes volumes de ER, realizados em uma única sessão, sobre a vasodilatação dependente do endotélio e síntese de óxido nítrico (NO) em artéria mesentérica de animais saudáveis. Métodos: Ratos Wistar machos foram divididos em três grupos: Controle (Ct); baixo volume (BV, 5 séries x 10 repetições) e alto volume de ER (AV, 15 séries x 10 repetições). Foi estabelecida a intensidade de 70% do teste de repetição máxima. Após o protocolo de exercício, anéis de artéria mesentérica foram utilizados na avaliação da reatividade vascular, e outras artérias mesentéricas foram preparadas para a detecção da produção de NO por fluorescência com para do DAF-FM. A resposta à insulina pela síntese de NO foi avaliada estimulando-se os anéis vasculares com insulina (10nM). Resultados: A resposta máxima do relaxamento induzido por insulina foi aumentada somente no grupo AV em comparação ao grupo Ct. Além disso, a inibição da síntese do NO (L-NAME), aboliu completamente o relaxamento vascular induzido por insulina em ratos exercitados. A produção de NO mostrou um aumento dependente do volume no endotélio e no músculo liso. No endotélio, apenas os grupos Ct e BV mostraram aumento significativo na síntese de NO quando comparado aos seus respectivos grupos sob condição basal. No entanto, no músculo liso, a fluorescência foi aumentada em todos os grupos quando comparados aos seus respectivos grupos sob a condição basal. Conclusões: Nossos resultados sugerem que uma única sessão de ER foi capaz de promover adaptações no endotélio vascular. Além disso, nós observamos que este efeito é volume-dependente e o volume de 15 séries x10 repetições induziu o maior aumento na síntese de NO.

Animals , Male , Physical Conditioning, Animal/physiology , Endothelium, Vascular/physiology , Endothelium-Dependent Relaxing Factors/physiology , Resistance Training , Nitric Oxide/physiology , Vasodilation/drug effects , Vasodilator Agents/pharmacology , Endothelium, Vascular/drug effects , Random Allocation , Rats, Wistar , NG-Nitroarginine Methyl Ester/pharmacology , Enzyme Inhibitors/pharmacology , Insulin/pharmacology , Mesenteric Arteries/drug effects , Mesenteric Arteries/physiology
Rev. bras. cir. cardiovasc ; 32(2): 125-135, Mar.-Apr. 2017. tab
Article in English | LILACS | ID: biblio-843476


Abstract The endothelium plays an important role in maintaining vascular homeostasis and regulating blood vessel function. Endothelial function is considered an independent predictor for risk of future cardiovascular events in cardiovascular and non-cardiovascular patients, as well as a predictor for postoperative complications in cardiovascular surgery patients. Brachial artery flow-mediated dilation by high-resolution ultrasound is widely used to evaluate endothelium-dependent vasodilation, which is mainly mediated by nitric oxide release. Physical exercise exerts beneficial effects on endothelial function and can be used in both primary and secondary prevention of cardiac and peripheral artery diseases, even in the postoperative period of cardiovascular surgery.

Humans , Endothelium, Vascular/physiology , Biomarkers , Cardiovascular Diseases/diagnosis , Cardiac Rehabilitation/methods , Postoperative Complications/prevention & control , Primary Prevention/methods , Blood Circulation/physiology , Brachial Artery/physiology , Cardiovascular Diseases/surgery , Cardiovascular Diseases/prevention & control , Exercise/physiology , Secondary Prevention/methods
Arq. bras. cardiol ; 108(4): 315-322, Apr. 2017. graf
Article in English | LILACS | ID: biblio-838719


Abstract Background: The practice of exercise in short bouts repeated throughout the day may be an alternative strategy to lift people out of physical inactivity. Objective: to evaluate if accumulated exercise, as occurs in continuous exercise training, improve endothelial function in rat aorta. Methods: Wistar male rats were divided into three groups: continuous exercise (CEx, 1 hour on the treadmill) or accumulated exercise (AEx, 4 bouts of 15 minutes / day) for 5 days/week for 8 weeks, or sedentary (SED). During the training period, body weight gain and increase in exercise performance were recorded. On sacrifice day, aorta was dissected into rings (3-5 mm) and mounted on the organ bath. Results: Fitness was significantly greater in CEx and AEx rats as compared with SED animals. In addition, compared with the SED group, CEx animals had a lower body mass gain, and the aorta obtained from these animals had reduced contractile response to norepinephrine and greater acetylcholine-induced relaxation. These results were not observed in ACEx animals. Conclusions: Both CEx and AEx improved fitness, but only CEx led to reduced body weight gain and improved endothelial function.

Resumo Fundamento: A prática de exercícios em sessões curtas que se repetem ao longo do dia pode ser uma alternativa para tirar as pessoas da inatividade física. Objetivo: Verificar se o exercício acumulado, tal como ocorre com o treinamento com exercício contínuo, melhora a função endotelial na aorta de ratos. Métodos: Ratos Wistar machos foram divididos em 3 grupos: treinamento com exercício contínuo (ExC; 1 hora em esteira) ou com exercício acumulado (ExA; 4 sessões de 15 minutos ao longo do dia) por 5 dias/semana, durante 8 semanas, ou grupo sedentário (SED). Durante o treinamento, foram registrados o ganho de peso corporal e desempenho na esteira. No dia do sacrifício, anéis (3-5 mm) da aorta foram obtidos e montados em banho de órgãos. Resultados: Animais ExC e ExA mostraram aptidão física significativamente maior em comparação com os SED. Paralelamente, em comparação com SED, animais ExC tiveram menor ganho de massa corporal, e aortas retiradas desses animais mostraram respostas contrácteis à noradrenalina reduzidas e maior relaxamento induzido pela acetilcolina. Esses resultados não foram observados no grupo ExA. Conclusões: Tanto o ExC quanto o ExA melhoraram a aptidão física, mas somente o ExC foi capaz de reduzir o ganho de peso corporal dos animais e melhorar a função endotelial.

Animals , Male , Aorta/physiology , Physical Conditioning, Animal/methods , Endothelium, Vascular/physiology , Physical Fitness/physiology , Aorta/drug effects , Physical Conditioning, Animal/physiology , Vasoconstrictor Agents/pharmacology , Endothelium, Vascular/drug effects , Weight Loss/physiology , Acetylcholine/pharmacology , Random Allocation , Norepinephrine/pharmacology , Thiobarbituric Acid Reactive Substances/analysis , Rats, Wistar , Models, Animal
Arq. bras. cardiol ; 108(2): 116-121, Feb. 2017. tab, graf
Article in English | LILACS | ID: biblio-838695


Abstract Background: Despite knowing that resveratrol has effects on blood vessels, blood pressure and that phytostrogens can also improve the endothelium-dependent relaxation/vasodilation, there are no reports of reveratrol's direct effect on the endothelial function and blood pressure of animals with estrogen deficit (mimicking post-menopausal increased blood pressure). Objective: To verify the effect of two different periods of preventive treatment with resveratrol on blood pressure and endothelial function in ovariectomized young adult rats. Methods: 3-month old female Wistar rats were used and distributed in 6 groups: intact groups with 60 or 90 days, ovariectomized groups with 60 or 90 days, and ovariectomized treated with resveratrol (10 mg/kg of body weight per day) for 60 or 90 days. The number of days in each group corresponds to the duration of the experimental period. Vascular reactivity study was performed in abdominal aortic rings, systolic blood pressure was measured and serum nitric oxide (NO) concentration was quantified. Results: Ovariectomy induced blood pressure increase 60 and 90 days after surgery, whereas the endothelial function decreased only 90 days after surgery, with no difference in NO concentration among the groups. Only longer treatment (90 days) with resveratrol was able to improve the endothelial function and normalize blood pressure. Conclusion: Our results suggest that 90 days of treatment with resveratrol is able to improve the endothelial function and decrease blood pressure in ovariectomized rats.

Resumo Fundamentos: Apesar de se saber que o resveratrol apresenta efeitos sobre a pressão arterial e os vasos sanguíneos, e que os fitoestrógenos podem melhorar o relaxamento/vasodilatação dependente do endotélio, não há relatos do efeito direto do resveratrol sobre a pressão arterial e a função endotelial em animais com deficiência de estrógeno (mimetizando a pressão arterial aumentada pós-menopausa). Objetivo: Verificar o efeito de dois diferentes períodos de tratamento preventivo com resveratrol sobre a pressão arterial e a função endotelial em ratas adultas jovens ovariectomizadas. Métodos: Foram utilizadas ratas Wistar com 3 meses de idade, distribuídas em 6 grupos: grupos intactas com 60 ou 90 dias, grupos ovariectomizadas com 60 ou 90 dias, grupos ovariectomizadas e tratadas com resveratrol na dose de 10mg/kg de massa corporal por dia, durante 60 ou 90 dias, sendo o número de dias em cada grupo relativo à duração do período experimental. Foi realizado um estudo de reatividade vascular em anéis da aorta abdominal, mensurada a pressão arterial sistólica e quantificada a concentração sérica de óxido nítrico (NO). Resultados: A ovariectomia induziu aumento da pressão arterial 60 e 90 dias após a cirurgia, enquanto a função endotelial decaiu apenas após 90 dias, e não houve diferença na concentração de NO entre os grupos. Apenas o tratamento prolongado com resveratrol (90 dias) foi capaz de melhorar a função endotelial e normalizar a pressão arterial. Conclusão: Nossos resultados sugerem que o tratamento por 90 dias com resveratrol é capaz de melhorar a função endotelial e diminuir a pressão sanguínea em ratas ovariectomizadas.

Animals , Female , Stilbenes/pharmacology , Blood Pressure/drug effects , Endothelium, Vascular/drug effects , Ovariectomy , Antioxidants/pharmacology , Reference Values , Stilbenes/therapeutic use , Time Factors , Blood Pressure/physiology , Endothelium, Vascular/physiology , Reproducibility of Results , Treatment Outcome , Rats, Wistar , Estrogens/deficiency , Resveratrol , Hypertension/metabolism , Hypertension/drug therapy , Nitrates/blood , Nitric Oxide/blood , Antioxidants/therapeutic use
Braz. j. med. biol. res ; 49(5): e5058, 2016. tab, graf
Article in English | LILACS | ID: biblio-951680


The relaxation of coronary arteries by estrogens in the coronary vascular beds of naive and hypertensive rats has been well described. However, little is known about this action in gonadectomized rats. We investigated the effect of 17-ß-estradiol (E2) in coronary arteries from gonadectomized rats, as well as the contributions of endothelium-derived factors and potassium channels. Eight-week-old female and male Wistar rats weighing 220-300 g were divided into sham-operated and gonadectomized groups (n=9−12 animals per group). The baseline coronary perfusion pressure (CPP) was determined, and the vasoactive effects of 10 μM E2 were assessed by bolus administration before and after endothelium denudation or by perfusion with NG-nitro-L-arginine methyl ester (L-NAME), indomethacin, clotrimazole, L-NAME plus indomethacin, L-NAME plus clotrimazole or tetraethylammonium (TEA). The CPP differed significantly between the female and sham-operated male animals. Gonadectomy reduced the CPP only in female rats. Differences in E2-induced relaxation were observed between the female and male animals, but male castration did not alter this response. For both sexes, the relaxation response to E2 was, at least partly, endothelium-dependent. The response to E2 was reduced only in the sham-operated female rats treated with L-NAME. However, in the presence of indomethacin, clotrimazole, L-NAME plus indomethacin or L-NAME plus clotrimazole, or TEA, the E2 response was significantly reduced in all groups. These results highlight the importance of prostacyclin, endothelium-derived hyperpolarizing factor, and potassium channels in the relaxation response of coronary arteries to E2 in all groups, whereas nitric oxide may have had an important role only in the sham-operated female group.

Animals , Male , Female , Rats , Gonadal Steroid Hormones/deficiency , Vasodilation/drug effects , Vasodilator Agents/pharmacology , Endothelium, Vascular/drug effects , Coronary Vessels/drug effects , Estradiol/pharmacology , Heart/drug effects , Endothelium, Vascular/physiology , Orchiectomy , Ovariectomy , Rats, Wistar , Coronary Vessels/physiology
Acta odontol. latinoam ; 29(1): 60-67, 2016. tab, ilus
Article in English | LILACS | ID: lil-790209


There is a relation between vascular endothelial function,atherosclerotic disease, and inflammation. Deterioration ofendothelial function has been observed twenty-four hours afterintensive periodontal treatment. This effect may be counteractedby the action of angiotensin-converting enzyme inhibitors, whichimprove endothelial function. The aim of the present study was toevaluate vascular endothelial function after intensive periodontaltreatment, in hypertensive patients treated with angiotensin-converting enzyme inhibitors. A prospective, longitudinal, comparative study involving repeatedmeasurements was conducted. Fifty-two consecutive patients withsevere periodontal disease were divided into two groups, onecomprising hypertensive patients treated with converting enzymeinhibitors and the other comprising patients with no clinical signsof pathology and not receiving angiotensin-converting enzymeinhibitors. Endothelial function was assessed by measuring post-ischemic dilation of the humeral artery (baseline echocardiographyDoppler), and intensive periodontal treatment was performed 24hlater. Endothelial function was re-assessed 24h and 15 days after periodontal treatment. Statistical analysis: Results were analyzedusing the SPSS 20 statistical software package. Student’s t test andMANOVA were calculated and linear regression analysis with 95%confidence intervals and α<0.05 was performed. Arterial dilationat 24 hours was lower compared to baseline in both groups; valuescorresponding to the groups receiving angiotensin-convertingenzyme inhibitors were 11.89 ± 4.87 vs. 7.30 ± 2.90% (p<0.01) andthose corresponding to the group not receiving ACE inhibitors were12.72 ± 4.62 vs. 3.56 ± 2.39 (p<0.001). The differences betweengroups were statistically significant (p<0.001)...

Existe relación entre la disfunción del endotelio vascular, la enfermedad ateroesclerótica y la inflamación. A las 24 horas del tratamiento intensivo de la enfermedad periodontal, se produce un deterioro de la función endotelial. Este efecto podría ser balanceado por la acción de los inhibidores de la enzima convertidora de la angiotensina que mejoran la función endotelial. El objetivo del presente estudio fue evaluar la función endotelial vascular después del tratamiento periodontal intensivo, en pacientes hipertensos tratados con inhibidores de la enzima convertidora de la angiotensina. Se realizó un estudio prospectivo, longitudinal, comparativo, con mediciones repetidas. Se incorporaron 52 pacientes con enfermedad periodontal severa divididos en dos grupos, uno con hipertensión arterial, tratados con inhibidores de la enzima convertidora y otro sin inhibidores ni patología clínicamente evidente. Se determinó la función endotelial cuantificando la dilatación de la arterial humeral post isquemia ecocardiografía Doppler basal. A las 24 hs se efectuó el tratamiento periodontal intensivo; a las 24 h y 15 días posteriores se reevaluó la función endotelial. Análisis estadístico: se empleó el paquete estadístico SPSS 20. Se realizaron: t-test de Student, MANOVA y análisis de regresión lineal con intervalos de confianza del 95 por ciento y a <0.05. Resultados: a las 24 h post tratamiento periodontal, se observó una menor dilatación arterial en ambos grupos, en relación a la dilatación arterial basal, siendo para el grupo con inhibidores 11.89 +- 4.87 vs. 7.30 +- 2.90 por ciento, p<0.01 y para el grupo sin inhibidores 12.72 +- 4.62 vs. 3.56 +- 2.39, p<0.001, con diferencias significativas entre ambos p<0.001...

Humans , Male , Adult , Female , Angiotensin-Converting Enzyme Inhibitors , Periodontal Diseases/therapy , Hypertension/epidemiology , Argentina , Dental Service, Hospital , Echocardiography, Doppler/methods , Endothelium, Vascular/physiology , Longitudinal Studies , Prospective Studies , Data Interpretation, Statistical
Braz. j. med. biol. res ; 49(4): e5100, 2016. tab, graf
Article in English | LILACS | ID: lil-774527


This study aimed to examine the time course of endothelial function after a single handgrip exercise session combined with blood flow restriction in healthy young men. Nine participants (28±5.8 years) completed a single session of bilateral dynamic handgrip exercise (20 min with 60% of the maximum voluntary contraction). To induce blood flow restriction, a cuff was placed 2 cm below the antecubital fossa in the experimental arm. This cuff was inflated to 80 mmHg before initiation of exercise and maintained through the duration of the protocol. The experimental arm and control arm were randomly selected for all subjects. Brachial artery flow-mediated dilation (FMD) and blood flow velocity profiles were assessed using Doppler ultrasonography before initiation of the exercise, and at 15 and 60 min after its cessation. Blood flow velocity profiles were also assessed during exercise. There was a significant increase in FMD 15 min after exercise in the control arm compared with before exercise (64.09%±16.59%, P=0.001), but there was no change in the experimental arm (-12.48%±12.64%, P=0.252). FMD values at 15 min post-exercise were significantly higher for the control arm in comparison to the experimental arm (P=0.004). FMD returned to near baseline values at 60 min after exercise, with no significant difference between arms (P=0.424). A single handgrip exercise bout provoked an acute increase in FMD 15 min after exercise, returning to near baseline values at 60 min. This response was blunted by the addition of an inflated pneumatic cuff to the exercising arm.

Humans , Male , Adult , Endothelium, Vascular/physiology , Exercise/physiology , Analysis of Variance , Blood Flow Velocity/physiology , Endothelium, Vascular/diagnostic imaging , Hand Strength/physiology , Reference Values , Risk Factors , Shear Strength/physiology , Statistics, Nonparametric , Time Factors , Ultrasonography, Doppler
Arq. bras. cardiol ; 105(6): 597-605, Dec. 2015. tab, graf
Article in Portuguese | LILACS | ID: lil-769538


Abstract Background: Studies suggest that statins have pleiotropic effects, such as reduction in blood pressure, and improvement in endothelial function and vascular stiffness. Objective: To analyze if prior statin use influences the effect of renin-angiotensin-aldosterone system inhibitors on blood pressure, endothelial function, and vascular stiffness. Methods: Patients with diabetes and hypertension with office systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 80 mmHg had their antihypertensive medications replaced by amlodipine during 6 weeks. They were then randomized to either benazepril or losartan for 12 additional weeks while continuing on amlodipine. Blood pressure (assessed with ambulatory blood pressure monitoring), endothelial function (brachial artery flow-mediated dilation), and vascular stiffness (pulse wave velocity) were evaluated before and after the combined treatment. In this study, a post hoc analysis was performed to compare patients who were or were not on statins (SU and NSU groups, respectively). Results: The SU group presented a greater reduction in the 24-hour systolic blood pressure (from 134 to 122 mmHg, p = 0.007), and in the brachial artery flow-mediated dilation (from 6.5 to 10.9%, p = 0.003) when compared with the NSU group (from 137 to 128 mmHg, p = 0.362, and from 7.5 to 8.3%, p = 0.820). There was no statistically significant difference in pulse wave velocity (SU group: from 9.95 to 9.90 m/s, p = 0.650; NSU group: from 10.65 to 11.05 m/s, p = 0.586). Conclusion: Combined use of statins, amlodipine, and renin-angiotensin-aldosterone system inhibitors improves the antihypertensive response and endothelial function in patients with hypertension and diabetes.

Resumo Fundamentos: Estudos sugerem que as estatinas possuem efeitos pleotrópicos, como melhora da função endotelial, da rigidez vascular e redução da pressão arterial. Objetivo: Analisar se o uso prévio de estatina influenciou o efeito sobre a pressão arterial, a função endotelial e a rigidez vascular de drogas inibidoras do sistema renina-angiotensina-aldosterona. Métodos: Pacientes hipertensos e diabéticos com pressão arterial de consultório sistólica ≥ 130 mmHg e/ou diastólica ≥ 80 mmHg tiveram suas medicações anti-hipertensivas substituídas por anlodipino durante 6 semanas. Em seguida, foram randomizados para associação de benazepril ou losartana por mais 12 semanas. Pressão arterial (através da monitorização ambulatorial da pressão arterial), função endotelial (dilatação mediada por fluxo da artéria braquial) e rigidez vascular (velocidade da onda de pulso) foram avaliados antes e após o tratamento combinado. Neste trabalho, uma análise post-hoc foi realizada para comparar pacientes que vinham (grupo CE) ou não (grupo SE) em uso de estatina. Resultados: O grupo CE apresentou maior redução na pressão arterial sistólica nas 24 horas (134 para 122 mmHg, p = 0,007) e na dilatação mediada por fluxo da artéria braquial (6,5 para 10,9%, p = 0,003) quando comparado com o grupo SE (137 para 128 mmHg, p = 0,362, e 7,5 para 8,3%, p = 0,820). Não houve diferença estatisticamente significante na velocidade de onda de pulso (grupo CE 9,95 para 9,90 m/s, p = 0,650 e grupo SE 10,65 para 11,05 m/s, p = 0,586). Conclusão: O uso combinado de estatinas, anlodipino e inibidores do sistema renina-angiotensina-aldosterona melhora a resposta anti-hipertensiva e a função endotelial em pacientes hipertensos e diabéticos.

Female , Humans , Male , Middle Aged , Amino Acids/pharmacology , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Antihypertensive Agents/pharmacology , /drug therapy , Endothelium, Vascular/drug effects , Hypertension/drug therapy , Renin-Angiotensin System/drug effects , Amino Acids/therapeutic use , Amlodipine/pharmacology , Amlodipine/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Antihypertensive Agents/therapeutic use , Blood Pressure Monitoring, Ambulatory , Benzazepines/pharmacology , Benzazepines/therapeutic use , Blood Pressure/drug effects , Brachial Artery/drug effects , Endothelium, Vascular/physiology , Losartan/pharmacology , Losartan/therapeutic use , Pulse Wave Analysis , Statistics, Nonparametric , Time Factors , Treatment Outcome , Vascular Stiffness/drug effects
Einstein (Säo Paulo) ; 13(3): 395-403, July-Sep. 2015. graf
Article in English | LILACS | ID: lil-761966


Objective To describe and to characterize the relaxing effect of an extract of the bark of Combretum leprosum on isolated arterial rings from different animals.Methods Rings (3 to 4mm) from rabbit, rat, or porcine arteries rings were suspended in an organ bath (Krebs, 37°C, 95%O2/5%CO2) to record isometric contractions. After the stabilization period (2 to 3 hours) contractions were induced by the addition of phenylephrine (0.1 to 0.3µM) or U46619 (10 to 100nM), and Combretum leprosum extract was added on the plateau of the contractions. Experiments were performed to determine the potency, duration, reversibility, and to get insights on the potential mechanism involved in extract-induced relaxations.Results In all rings tested, Combretumleprosum extract (1.5μg/mL) was able to cause relaxations, which were strictly endothelium-dependent. In rabbit or rat thoracic aorta rings, the relaxations were reversed by vitamin B12a or L-NG-nitroarginine. In porcine right coronary arteries and rabbit abdominal aorta, extract caused both L-NG-nitroarginine-sensitive and L-NG-nitroarginine-resistant relaxations. In rabbit thoracic aorta, the extract was relatively potent (EC50=0.20µg/mL) and caused relaxations; intriguingly the endothelium continued to produce relaxing factors for a long period after removing the extract. The magnitude of extract-induced relaxations was significantly reduced in the absence of extracellular Ca2+; in addition, the TRPs channels blocker ruthenium red (10µM) was able to revert extract-induced relaxations. Phytochemical analyses indicated that the extract was rich in polyphenol-like reacting substances.ConclusionsCombretum leprosum extract contains bioactive compounds capable of promoting Ca2+-dependent stimulation of endothelial cells which results in a prolonged production of relaxing factors.

Objetivo Descrever e caracterizar os relaxamentos induzidos por um extrato das cascas de Combretum leprosum em anéis de artérias de diferentes espécies de animais.Métodos Anéis (3 a 4mm) de artérias de coelho, rato e porco foram montados em cubas para órgão isolado (Krebs, 37°C, 95%O2/5%CO2) para registro das contrações isométricas. Após um período de estabilização (2 a 3 horas), as contrações foram induzidas com fenilefrina (0,1 a 0,3µM) ou U46619 (10 a 100nM); no platô dessas contrações, adicionamos o extrato Combretum leprosum. Diferentes protocolos foram realizados para determinar potência, duração, reversibilidade e mecanismo dos relaxamentos induzidos pelo extrato.Resultados Em todas as preparações testadas, o extrato de Combretum leprosum (1,5µg/mL) provocou relaxamentos dependentes de endotélio. Em aorta torácica de coelho ou rato, os relaxamentos foram revertidos pela vitamina B12a ou L-NG-nitro-arginina. Em anéis de aorta abdominal de coelho e de artérias coronárias de porco, o extrato causou relaxamentos sensíveis e resistentes à L-NG-nitro-arginina. Em aorta torácica de coelho, o extrato foi relativamente muito potente (EC50=0,20μg/mL) e quando causou relaxamentos; intrigantemente o endotélio continuou a produzir fatores relaxantes por um longo período após remoção do extrato. A magnitude dos relaxamentos induzidos pelo extrato foi significativamente reduzida em ausência Ca2+ extracelular; ademais, o vermelho de rutênio (10μM), um bloqueador de canais TRPs, foi capaz de reverter os relaxamentos induzidos pelo extrato. Análises preliminares indicaram que o extrato continha compostos com reatividade química semelhante à polifenóis.Conclusão O extrato de Combretum leprosum contem compostos bioativos capazes de promover estimulação dependente de Ca2+ das células endoteliais a qual resulta numa produção prolongada de fatores relaxantes.

Animals , Female , Guinea Pigs , Male , Mice , Rabbits , Combretum/chemistry , Endothelium-Dependent Relaxing Factors/pharmacology , Muscle Relaxation/drug effects , Nitric Oxide/pharmacology , Acetylcholine/pharmacology , Aorta, Abdominal/drug effects , Aorta, Abdominal/physiology , Aorta, Thoracic/drug effects , Aorta, Thoracic/physiology , Carotid Artery, Common/drug effects , Carotid Artery, Common/physiology , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiology , Mesenteric Artery, Superior/drug effects , Mesenteric Artery, Superior/physiology , Muscle Relaxation/physiology , Plant Bark/chemistry , Rats, Wistar , Swine , Time Factors
Rev. cuba. endocrinol ; 26(2): 138-146, mayo.-ago. 2015. ilus, tab
Article in Spanish | LILACS, CUMED | ID: lil-749599


Introducción: La disminución de los estrógenos durante el climaterio repercute negativamente en el endotelio vascular, y origina disfunción endotelial, cuyo significado clínico está aún por definir. Objetivo: determinar la frecuencia de disfunción endotelial en las etapas del climaterio. Métodos: estudio descriptivo transversal, en 133 mujeres de 40-59 años, sin factores de riesgo cardiovascular, seleccionadas en centros de los 3 niveles de atención del Sistema Nacional de Salud, entre mayo de 2012 y mayo de 2013. Se evaluó la función endotelial mediante la prueba de dilatación mediada por el flujo de la arteria braquial, y su relación con etapas del climaterio. Se exploró la asociación entre variables utilizando pruebas no paramétricas (Kruskal-Wallis). Resultados: en el 38 por ciento de las mujeres se encontró disfunción endotelial, más frecuente en la etapa temprana de la posmenopausia respecto a la tardía y a la perimenopausia (45,0 vs. 27,5 vs. 27,5 por ciento respectivamente [p< 0,05]). Conclusiones: la disfunción endotelial es un evento frecuente en las mujeres de edad mediana aparentemente sanas, y al parecer, el descenso inicial de los estrógenos en los primeros años de la posmenopausia, tiene mayor impacto negativo en el endotelio vascular que el tiempo de exposición al hipoestrogenismo(AU)

Introduction: Estrogen reduction during the climacteric has a negative effect on the vascular endothelium and causes endothelial dysfunction, whose clinical significance is still to be defined.Objective: determine the frequency of endothelial dysfunction in the different stages of climacteric. Methods: a descriptive cross-sectional study was conducted of 133 women aged 40-59 with no cardiovascular risk factors, selected from institutions of the three health care levels within the National Health System from May 2012 to May 2013. Endothelial function was evaluated using the brachial artery flow-mediated dilation test and its association with climacteric stages. The relationship between variables was analyzed using non-parametric tests (Kruskal-Wallis). Results: 38 percent of the women had endothelial dysfunction, which was more common in the early stage of post-menopause than in the late stage and in perimenopause (45.0 vs. 27.5 vs. 27.5 percent, respectively [p< 0.05]). Conclusions: endothelial dysfunction is a common event among seemingly healthy middle-aged women. It seems that the initial reduction in estrogens in the first years of post-menopause has a greater negative impact on the vascular endothelium than the time of exposure to hypoestrogenism(AU)

Humans , Female , Climacteric/physiology , Menopause/physiology , Endothelium, Vascular/physiology , Estrogens/deficiency , Epidemiology, Descriptive , Cross-Sectional Studies/methods
Int. j. cardiovasc. sci. (Impr.) ; 28(2): 89-94, mar.-abr. 2015. tab, graf
Article in English, Portuguese | LILACS | ID: lil-762448


Introdução: O chocolate amargo melhora a função endotelial, porém existem poucos dados sobre sua ação em pacientes com doença coronariana.Objetivo: Avaliar a função endotelial de pacientes com síndrome coronariana aguda após o consumo de chocolateamargo e de chocolate branco.Métodos: Trata-se de ensaio clínico randomizado e cruzado que avaliou 11 pacientes internados com síndrome coronariana aguda. Os pacientes foram selecionados para receber chocolate amargo ou chocolate branco e cruzados para receber a outra intervenção após sete dias. O desfecho primário foi a variação na vasodilatação fluxo-mediada da artéria braquial pré e pós-intervenção nos dois grupos. Os desfechos secundários foram os valores da vasodilatação fluxo-mediada e dodiâmetro da artéria braquial após a intervenção, os níveis de proteína C-reativa ultrassensível (PCRus) e da velocidade de hemossedimentação (VHS), pressão arterial sistólica (PAS) e diastólica (PAD) e frequência cardíaca (FC). Resultados: A variação da vasodilatação fluxo-mediada pré e pós-intervenção foi superior no grupo que recebeu o chocolate amargo quando comparada com o grupo que recebeu chocolate branco. Ambos os grupos apresentaram aumento significativoda vasodilatação fluxo-mediada após intervenção. A vasodilatação fluxo-mediada pós-intervenção, contudo, mostrou-se superior no grupo que recebeu chocolate amargo (0,32±0,10) quando comparada ao chocolate branco (0,21±0,11) (p=0,001). Não houve diferenças significativas nos valores de PCRus, VHS, PAS, PAD ou FC.Conclusão: O consumo de chocolate melhora a função endotelial em pacientes pós-síndrome coronariana aguda e este efeito é mais pronunciado com o consumo de chocolate amargo.

Introduction: Unsweetened chocolate improves endothelial function, but there are few data on its action in patients with coronary disease. Objective: To assess the endothelial function in patients with acute coronary syndrome after consumption of unsweetened chocolate and white chocolate. Methods: This is a randomized crossover clinical trial that evaluated 11 patients admitted with acute coronary syndrome. The patients were selected to receive unsweetened chocolate or white chocolate and crossed over to receive the other intervention after seven days. The primary outcome was the variation in flow-mediated vasodilation of the brachial artery pre and post interventionin both groups. The secondary outcomes were the values of flow-mediated vasodilation and the diameter of the brachial artery after the intervention, the levels of high-sensitivity C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR), systolic bloodpressure (SBP) and diastolic blood pressure (DBP) and heart rate (HR).Results: The variation of flow-mediated vasodilation pre and post intervention was higher in the group that received the unsweetened chocolate compared with the group that received white chocolate. Both groups showed a significant increase in flow-mediatedvasodilation after intervention. The flow-mediated vasodilation after intervention, however, was higher in the group receiving unsweetened chocolate (0.32±0.10) compared to white chocolate (0.21±0.11) (p=0.001). There were no significant differences inhsCRP, ESR, SBP, DBP or HR values. Conclusion: The consumption of chocolate improves endothelial function in patients after acute coronary syndrome patients and this effect is more pronounced with the consumption of unsweetened chocolate.

Humans , Male , Female , Middle Aged , Cacao , Endothelium, Vascular/physiology , Patients , Acute Coronary Syndrome/physiopathology , Ultrasonography/methods , Analysis of Variance , Brachial Artery , Blood Sedimentation , Heart Rate/physiology , Arterial Pressure/physiology , C-Reactive Protein/analysis
Braz. dent. j ; 25(5): 435-441, Sep-Oct/2014. tab, graf
Article in English | LILACS | ID: lil-731060


This study compared the physicochemical properties and interfacial adaptation to canal walls of Endo-CPM-Sealer, Sealapex and Activ GP with the well-established AH Plus sealer. The following analyses were performed: radiopacity, pH variation and solubility using samples of each material and scanning electron microscopy of root-filled bovine incisors to evaluate the interfacial adaptation. Data were analyzed by the parametric and no-parametric tests (α=0.05). All materials were in accordance with the ANSI/ADA requirements for radiopacity. Endo-CPM-Sealer presented the lowest radiopacity values and AH Plus was the most radiopaque sealer (p=0.0001). Except for ActiV GP, which was acidic, all other sealers had basic chemical nature and released hydroxyl ions. Regarding solubility, all materials met the ANSI/ADA recommendations, with no statistically significant difference between the sealers (p=0.0834). AH Plus presented the best adaptation to canal walls in the middle (p=0.0023) and apical (p=0.0012) thirds, while the sealers Activ GP and Endo-CPM-Sealer had poor adaptation to the canal walls. All sealers, except for ActiV GP, were alkaline and all of them fulfilled the ANSI/ADA requirements for radiopacity and solubility. Regarding the interfacial adaptation, AH Plus was superior to the others considering the adaptation to the bovine root canal walls.

Este estudo comparou as propriedades físico-químicas e a adaptação interfacial às paredes do canal dos cimentos Endo-CPM-Sealer, Sealapex e Activ GP com o bem estabelecido cimento AH Plus. As seguintes análises foram realizadas: radiopacidade, variação de pH e de solubilidade utilizando amostras de cada material, e microscopia eletrônica de varredura utilizando incisivos bovinos obturados para avaliar a adaptação interfacial. Os dados foram analisados utilizando testes paramétricos e não-paramétricos (α=0,05). Todos os materiais estavam de acordo com os requerimentos da ANSI/ADA para radiopacidade, sendo que o Endo-CPM-Sealer apresentou os menores valores de radiopacidade e o AH Plus foi o cimento mais radiopaco (p=0,0001). Exceto o Activ GP, que foi ácido, todos os outros cimentos apresentaram natureza química básica e liberaram íons hidroxila. Com relação à solubilidade, todos os materiais estavam de acordo com as recomendações da ANSI /ADA, sem diferença significante entre os cimentos (p=0,0834). O AH Plus apresentou a melhor adaptação às paredes do canal nos terços médio (p=0,0023) e apical (p=0,0012), enquanto que os cimentos Activ GP e Endo-CPM-Sealer apresentaram uma pobre adaptação às paredes do canal. Em conclusão, todos os cimentos, exceto o Activ GP, foram alcalinos e todos preencheram os requerimentos da ANSI/ADA para radiopacidade e solubilidade. Com relação à adaptação interfacial, o AH Plus foi superior aos demais para adaptação às paredes do canal radicular de incisivos bovinos.

Animals , Female , Humans , Mice , Angiogenesis Inhibitors/pharmacology , Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Dextrans/pharmacology , Growth Inhibitors/pharmacology , Tumor Cells, Cultured/drug effects , Tumor Cells, Cultured/pathology , Angiogenesis Inhibitors/therapeutic use , Antineoplastic Agents/therapeutic use , Culture Media, Conditioned/pharmacology , Dose-Response Relationship, Drug , Dextrans/chemistry , Dextrans/therapeutic use , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiology , Growth Inhibitors/therapeutic use , Mice, Inbred BALB C , Mice, Nude , Necrosis , Phenylacetates/pharmacology , Phenylacetates/therapeutic use , Xenograft Model Antitumor Assays/statistics & numerical data
Braz. j. med. biol. res ; 47(9): 789-798, 09/2014. graf
Article in English | LILACS | ID: lil-719317


We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT2R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT2R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca2+-free medium or the subsequent tonic constrictions induced by the addition of Ca2+ in the absence of agonists. Thus, the contractions induced by Ca2+ release from intracellular stores and Ca2+ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca2+ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca2+. Neither levels of angiotensins nor of AT2R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca2+ entry.

Animals , Male , Aorta, Thoracic/physiopathology , Aortic Coarctation/physiopathology , Calcium/metabolism , Endothelium, Vascular/physiology , Muscle, Smooth, Vascular/physiopathology , Protein Kinase C/antagonists & inhibitors , Vasoconstriction/physiology , Angiotensin I/analysis , Angiotensin II/analysis , Aorta, Thoracic/injuries , Aorta, Thoracic/surgery , Blotting, Western , Blood Pressure/physiology , Chromatography, High Pressure Liquid , Endothelium, Vascular/injuries , Muscle, Smooth, Vascular/metabolism , Neuromuscular Depolarizing Agents/pharmacology , Phenylephrine/pharmacology , Potassium/pharmacology , Protein Kinase C/metabolism , Radioimmunoassay , Rats, Wistar , /metabolism , Vasoconstriction/drug effects
Clinics ; 68(12): 1537-1542, dez. 2013. graf
Article in English | LILACS | ID: lil-697707


OBJECTIVES: Estrogen has been shown to play an important protective role in non-reproductive systems, such as the cardiovascular system. Our aim was to observe gender differences in vivo with regard to the increase in macromolecular permeability and leukocyte-endothelium interaction induced by ischemia/reperfusion as well as in microvascular reactivity to vasoactive substances using the hamster cheek pouch preparation. METHODS: Thirty-six male and 36 female hamsters, 21 weeks old, were selected for this study, and their cheek pouches were prepared for intravital microscopy. An increase in the macromolecular permeability of post-capillary venules was quantified as a leakage of intravenously injected fluorescein-labeled dextran, and the leukocyte-endothelium interaction was measured as the number of fluorescent rolling leukocytes or leukocytes adherent to the venular wall, labeled with rhodamin G, during reperfusion after 30 min of local ischemia. For microvascular reactivity, the mean internal diameter of arterioles was evaluated after the topical application of different concentrations of two vasoconstrictors, phenylephrine (α1-agonist) and endothelin-1, and two vasodilators, acetylcholine (endothelial-dependent) and sodium nitroprusside (endothelial-independent). RESULTS: The increase in macromolecular permeability induced by ischemia/reperfusion was significantly lower in females compared with males [19 (17-22) leaks/cm2 vs. 124 (123-128) leaks/cm2, respectively, p<0.001), but the number of rolling or adherent leukocytes was not different between the groups. Phenylephrine-induced arteriolar constriction was significantly lower in females compared with males [77 (73-102)% vs. 64 (55-69)%, p<0.04], but there were no detectable differences in endothelin-1-dependent vasoreactivity. Additionally, arteriolar vasodilatation elicited by acetylcholine or sodium nitroprusside did not differ between the groups. CONCLUSION: The ...

Animals , Cricetinae , Female , Male , Cardiovascular System/metabolism , Estrogens/metabolism , Microcirculation/physiology , Acetylcholine/pharmacology , Capillary Permeability , Cell Adhesion/physiology , Cheek/blood supply , Endothelium, Vascular/physiology , Leukocytes/physiology , Nitroprusside/pharmacology , Phenylephrine/pharmacology , Reperfusion Injury/metabolism , Sex Factors , Time Factors