Phosphorylated PKM2 regulates endothelium-dependent vasodilation in diabetes / 中南大学学报(医学版)

OBJECTIVES@#Endothelium-dependent vasodilation dysfunction is the pathological basis of diabetic macroangiopathy. The utilization and adaptation of endothelial cells to high glucose determine the functional status of endothelial cells. Glycolysis pathway is the major energy source for endothelial cells. Abnormal glycolysis plays an important role in endothelium-dependent vasodilation dysfunction induced by high glucose. Pyruvate kinase isozyme type M2 (PKM2) is one of key enzymes in glycolysis pathway, phosphorylation of PKM2 can reduce the activity of pyruvate kinase and affect the glycolysis process of glucose. TEPP-46 can stabilize PKM2 in its tetramer form, reducing its dimer formation and phosphorylation. Using TEPP-46 as a tool drug to inhibit PKM2 phosphorylation, this study aims to explore the impact and potential mechanism of phosphorylated PKM2 (p-PKM2) on endothelial dependent vasodilation function in high glucose, and to provide a theoretical basis for finding new intervention targets for diabetic macroangiopathy.@*METHODS@#The mice were divided into 3 groups: a wild-type (WT) group (a control group, C57BL/6 mice) and a db/db group (a diabetic group, db/db mice), which were treated with the sodium carboxymethyl cellulose solution (solvent) by gavage once a day, and a TEPP-46 group (a treatment group, db/db mice+TEPP-46), which was gavaged with TEPP-46 (30 mg/kg) and sodium carboxymethyl cellulose solution once a day. After 12 weeks of treatment, the levels of p-PKM2 and PKM2 protein in thoracic aortas, plasma nitric oxide (NO) level and endothelium-dependent vasodilation function of thoracic aortas were detected. High glucose (30 mmol/L) with or without TEPP-46 (10 μmol/L), mannitol incubating human umbilical vein endothelial cells (HUVECs) for 72 hours, respectively. The level of NO in supernatant, the content of NO in cells, and the levels of p-PKM2 and PKM2 protein were detected. Finally, the effect of TEPP-46 on endothelial nitric oxide synthase (eNOS) phosphorylation was detected at the cellular and animal levels.@*RESULTS@#Compared with the control group, the levels of p-PKM2 in thoracic aortas of the diabetic group increased (P<0.05). The responsiveness of thoracic aortas in the diabetic group to acetylcholine (ACh) was 47% lower than that in the control group (P<0.05), and that in TEPP-46 treatment group was 28% higher than that in the diabetic group (P<0.05), while there was no statistically significant difference in the responsiveness of thoracic aortas to sodium nitroprusside (SNP). Compared with the control group, the plasma NO level of mice decreased in the diabetic group, while compared with the diabetic group, the phosphorylation of PKM2 in thoracic aortas decreased and the plasma NO level increased in the TEPP-46 group (both P<0.05). High glucose instead of mannitol induced the increase of PKM2 phosphorylation in HUVECs and reduced the level of NO in supernatant (both P<0.05). HUVECs incubated with TEPP-46 and high glucose reversed the reduction of NO production and secretion induced by high glucose while inhibiting PKM2 phosphorylation (both P<0.05). At the cellular and animal levels, TEPP-46 reversed the decrease of eNOS (ser1177) phosphorylation induced by high glucose (both P<0.05).@*CONCLUSIONS@#p-PKM2 may be involved in the process of endothelium-dependent vasodilation dysfunction in Type 2 diabetes by inhibiting p-eNOS (ser1177)/NO pathway.

Guías para el diagnóstico y seguimiento de niños y adolescentes portadores de hipertensión portal / Guidelines for diagnosis and follow-up of children and adolescents with portal hypertension

La hipertensión portal es un síndrome complejo producido por un aumento de la resistencia al flujo venoso esplácnico a nivel de la vena porta o sus ramas, con una circulación sistémica hiperdinámica caracterizada por vasodilatación periférica y aumento del gasto cardíaco. El sitio de obstrucción al flujo portal puede ser prehepático (hígado normal), intrahepático (como en la cirrosis) o posthepático (síndrome de BuddChiari). En los pacientes pediátricos, las causas prehepáticas e intrahepáticas se reparten en proporciones casi iguales (aproximadamente el 50 % cada una). La expresión clínica y el impacto individual son muy variados, pero en todos los casos expresan un deterioro en la salud de los pacientes y la necesidad de corregir el problema, tanto en sus consecuencias como, idealmente, en sus causas.

Portal hypertension is a complex syndrome caused by increased resistance to the splachnic venous flow at the portal vein level, with a hyperdynamic systemic circulation characterized by peripheral vasodilation and high cardiac output. Portal flow can be obstructed at prehepatic (¨normal liver¨), intrahepatic (as in cirrhosis), or post-hepatic level (as in Budd-Chiari syndrome). In pediatric patients, prehepatic and intrahepatic causes are almost equally distributed (nearly 50% each). Clinical presentation and individual impact are heterogeneous, but in each case, it is the expression of a worsening condition and the need to solve the problem, either by treating its consequences or (ideally) its causes.

Pharmacodynamic Mechanism of Kuanxiong Aerosol for Vasodilation and Improvement of Myocardial Ischemia / 中国结合医学杂志

OBJECTIVE@#To explore the effect of Kuanxiong Aerosol (KXA) on isoproterenol (ISO)-induced myocardial injury in rat models.@*METHODS@#Totally 24 rats were radomly divided into control, ISO, KXA low-dose and high-dose groups according to the randomized block design method, and were administered by intragastric administration for 10 consecutive days, and on the 9th and 10th days, rats were injected with ISO for 2 consecutive days to construct an acute myocardial ischemia model to evaluate the improvement of myocardial ischemia by KXA. In addition, the diastolic effect of KXA on rat thoracic aorta and its regulation of ion channels were tested by in vitro vascular tension test. The influence of KXA on the expression of calcium-CaM-dependent protein kinase II (CaMK II)/extracellular regulated protein kinases (ERK) signaling pathway has also been tested.@*RESULTS@#KXA significantly reduced the ISO-induced increase in ST-segment, interventricular septal thickness, cardiac mass index and cardiac tissue pathological changes in rats. Moreover, the relaxation of isolated thoracic arterial rings that had been precontracted using norepinephrine (NE) or potassium chloride (KCl) was increased after KXA treatment in an endothelium-independent manner, and was attenuated by preincubation with verapamil, but not with tetraethylammonium chloride, 4-aminopyridine, glibenclamide, or barium chloride. KXA pretreatment attenuated vasoconstriction induced by CaCl2 in Ca2+-free solutions containing K+ or NE. In addition, KXA pretreatment inhibited accumulation of Ca2+ in A7r5 cells mediated by KCl and NE and significantly decreased p-CaMK II and p-ERK levels.@*CONCLUSION@#KXA may inhibit influx and release of calcium and activate the CaMK II/ERK signaling pathway to produce vasodilatory effects, thereby improving myocardial injury.

O efeito da atorvastatina + aspirina na função endotelial difere com a idade em pacientes com HIV: Um estudo de caso-controle / The effect of atorvastatin + aspirin on the endothelial function differs with age in patients with HIV: A case-control study

Resumo Fundamento Pacientes com HIV têm maior probabilidade de apresentar doenças cardiovasculares quando comparados à população em geral. Objetivo Este foi um estudo de caso-controle que teve como objetivo avaliar quais fatores estavam associados a uma redução na espessura médio-intimal da carótida (IMT) da carótida e ao aumento na dilatação mediada por fluxo (DMF) da artéria braquial em pacientes com HIV que receberam atorvastatina + aspirina por um período de 6 meses. Métodos Foi realizada uma análise secundária de um ensaio clínico, que incluiu pessoas vivendo com HIV e baixo risco cardiovascular. Um total de 38 pacientes alocados para o braço de intervenção e tratados por 6 meses com uma combinação de atorvastatina + aspirina foram incluídos. Todos os participantes foram submetidos a ultrassonografia da carótida e da artéria braquial, tanto no início quanto no final do estudo. Os casos que responderam com aumento >10% da dilatação braquial (DMF) e redução da espessura médio-intimal da carótida (IMT) foram considerados casos, e aqueles que não responderam foram considerados controles. Avaliamos os fatores associados às respostas positivas obtidas através da IMT e DMF. Resultados A redução do IMT não se associou significativamente a nenhum dos fatores de risco avaliados: idade (p = 0,211), sexo (p = 0,260), tabagismo (p = 0,131) ou tempo de diagnóstico do HIV (p = 0,836). Um aumento na DMF foi significativamente associado com a idade entre aqueles na faixa etária de 40-59 anos, p = 0,015 (OR = 4,37; IC 95%: 1,07-17,79). Conclusões Os indivíduos mais velhos foram mais propensos a apresentar um aumento na DMF após 6 meses de tratamento com atorvastatina + aspirina.

Abstract Background Patients with HIV are more likely to present with cardiovascular disease when compared to the general population. Objective This was a case-control study that aimed to assess which factors were associated with a reduction in the carotid intima-media thickness (IMT) and an increase in the brachial artery flow-mediated dilation (FMD) in HIV patients who received atorvastatin + aspirin during a period of 6 months. Methods A secondary analysis of a clinical trial was conducted, which included people living with HIV infection and low cardiovascular risk. A total of 38 patients allocated to the intervention arm and treated for 6 months with a combination of atorvastatin + aspirin were included. All participants underwent a carotid and brachial artery ultrasound, both at the beginning and the end of the study. Cases that responded with an increase of >10% of the brachial dilatation (FMD) and reduction of the carotid intima-media thickness (IMT) were considered cases, and those who did not respond were considered controls. We assessed the factors associated with the positive responses obtained through IMT and FMD. Results A reduction in the IMT was not significantly associated with any of the evaluated risk factors: age (p=0.211), gender (p=0.260), smoking (p=0.131) or time since HIV diagnosis (p=0.836). An increase in the FMD was significantly associated with age amongst those in the 40-59 age group, p = 0.015 (OR = 4.37; 95% CI: 1.07-17.79). Conclusions Older individuals were more likely to present with an increased FMD after 6 months of treatment with atorvastatin + aspirin.

Proteolytic activity of Triatoma infestans saliva associated with PAR-2 activation and vasodilation

Triatoma infestans (Hemiptera: Reduviidae) is a hematophagous insect and the main vector of Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae). In the present study, the authors investigated whether a serine protease activity from the saliva of T. infestans has a role in vasomotor modulation, and in the insect-blood feeding by cleaving and activating protease-activated receptors (PARs). Methods T. infestans saliva was chromatographed as previously reported for purification of triapsin, a serine protease. The cleavage activity of triapsin on PAR peptides was investigated based on FRET technology. Mass spectrometry was used to analyze the sites of PAR-2 peptide cleaved by triapsin. NO measurements were performed using the DAN assay (2,3-diaminonapthalene). The vasorelaxant activity of triapsin was measured in vessels with or without functional endothelium pre-contracted with phenylephrine (3 µM). Intravital microscopy was used to assess the effect of triapsin on mouse skin microcirculation. Results Triapsin was able to induce hydrolysis of PAR peptides and showed a higher preference for cleavage of the PAR-2 peptide. Analysis by mass spectrometry confirmed a single cleavage site, which corresponds to the activation site of the PAR-2 receptor. Triapsin induced dose-dependent NO release in cultured human umbilical vein endothelial cells (HUVECs), reaching a maximum effect at 17.58 nM. Triapsin purified by gel-filtration chromatography (10-16 to 10-9 M) was applied cumulatively to mouse mesenteric artery rings and showed a potent endothelium-dependent vasodilator effect (EC30 = 10-12 M). Nitric oxide seems to be partially responsible for this vasodilator effect because L-NAME (L-NG-nitroarginine methyl ester 300 µM), a nitric oxide synthetase inhibitor, did not abrogate the vasodilation activated by triapsin. Anti-PAR-2 antibody completely inhibited vasodilation observed in the presence of triapsin activity. Triapsin activity also induced an increase in the mouse ear venular diameter. Conclusion Data from this study suggest a plausible association between triapsin activity mediated PAR-2 activation and vasodilation caused by T. infestans saliva.(AU)

Antioxidative Propolis From Stingless Bees (Heterotrigona Itama) Preserves Endothelium-Dependent Aortic Relaxation of Diabetic Rats: The Role of Nitric Oxide and Cyclic Guanosine Monophosphate

Propolis from stingless bees (Heterotrigona itama) is a resinous compound that exhibits antihyperglycaemia, free radical scavenging, and cardioprotective properties. The effect of propolis on diabetic vessels has not been investigated. Thus, this research aimed to determine the effect of propolis supplementation on the level of antioxidants and its mechanism of action in the aorta of diabetic rats. Male Sprague-Dawley rats were divided into five groups (n=8/group): healthy (control), untreated diabetes (DM), metformin-treated diabetes (DM+M, 300 mg/kg/day metformin), propolis-treated diabetes (DM+P, 300 mg/kg/day propolis extract) and diabetes with combined treatment (DM+M+P, dosage as former). Oral supplementation was conducted for four weeks immediately upon successful induction of diabetes by streptozotocin (60 mg/kg, intraperitoneal injection). At the end of the study, the rats were euthanised, and thoracic aorta was processed into tissue homogenates to determine the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase-1 (GPx-1) and soluble receptor for advanced glycation end-products (sRAGE). Aorta segments were harvested to examine their relaxation response towards graded concentration of acetylcholine (Ach; 10-8-10-4) M following precontraction with phenylephrine (PE; 10-6 M). Vasorelaxation towards a cumulative dose of propolis (0.01-1.00%) using PE-precontracted healthy aorta (n=6/experiments) was investigated under various simulated conditions: physiological buffer, L-NAME (10-4 M), methylene blue (10-5 M), indomethacin (10-5 M) and elevated glucose (25 mM). Propolis maintained antioxidative enzymes and sRAGE decoy molecules in the aortic tissue of the diabetic rats. The amelioration of diabetes-induced impairment of endothelium-dependent relaxation by propolis was mediated through the nitric oxide(NO)-cyclic guanosine monophosphate (cGMP) pathway. This non-clinical study reports vasoprotective property of propolis in diabetes mellitus.

Dietary supplementation with whey protein improves systemic microvascular function in heart failure patients: a pilot study

Endothelial dysfunction is a well-known component of the pathophysiology of heart failure (HF), with proven prognostic value. Dietary supplementation with whey protein (WP) has been widely used to increase skeletal muscle mass, but it also has vascular effects, which are less understood. This study aimed to evaluate the effects of WP supplementation on the systemic microvascular function of HF patients. This was a blinded, randomized, placebo-controlled clinical trial that evaluated the effects of 12-week WP dietary supplementation on systemic microvascular function, in patients with HF New York Heart Association (NYHA) classes I/II. Cutaneous microvascular flow and reactivity were assessed using laser speckle contrast imaging, coupled with pharmacological local vasodilator stimuli. Fifteen patients (aged 64.5±6.2 years, 11 males) received WP supplementation and ten patients (aged 68.2±8.8 years, 8 males) received placebo (maltodextrin). The increase in endothelial-dependent microvascular vasodilation, induced by skin iontophoresis of acetylcholine, was improved after WP (P=0.03) but not placebo (P=0.37) supplementation. Moreover, endothelial-independent microvascular vasodilation induced by skin iontophoresis of sodium nitroprusside, was also enhanced after WP (P=0.04) but not placebo (P=0.42) supplementation. The results suggested that dietary supplementation with WP improved systemic microvascular function in patients with HF.

Uric acid as a predictor of endothelial dysfunction in patients with metabolic syndrome

ABSTRACT Objective: We conducted a study to examine the association of endothelial dysfunction and oxidative stress with uric acid levels in patients of metabolic syndrome. Subjects and methods: One hundred and two patients of Metabolic Syndrome (International Diabetes Federation definition) were included in the study. Anthropometric measurements, serum uric acid levels, fasting blood sugar levels and lipid levels, as well as malondialdehyde and reactive nitrogen intermediates were measured after an 8-hour fasting period. Flow mediated vasodilation (FMD) of the brachial artery was measured and endothelial dysfunction was defined as an increase in diameter < 10% post compression. Results: A total of 102 patients were included in the study. Mean uric acid level was 5.49 ± 1.61 mg%. A total of 59 patients in the study had endothelial dysfunction, defined by an abnormal FMD. Patients with an abnormal FMD had higher levels of serum uric acid which was statistically significant (p value = 0.010). Serum RNI and MDA levels were negatively correlated with uric acid, but did not reach statistical significance. Patients with an abnormal FMD had a lower RNI level, but this did not reach statistical significance. Serum MDA levels were significantly higher in patients with an abnormal FMD (p value = 0.038). Conclusions: Uric acid was significantly associated with endothelial dysfunction in patients with metabolic syndrome in our study. It was inversely correlated with serum RNI and MDA levels, but this did not reach statistical significance.

Efeito do Diterpeno Manool sobre a Pressão Arterial e Reatividade Vascular em Ratos Normotensos e Hipertensos / Effect of Diterpene Manool on the Arterial Blood Pressure and Vascular Reactivity in Normotensive and Hypertensive Rats

Resumo Fundamento: Diversos estudos têm mostrado que as classes de diterpenos exercem efeito significativo no sistema cardiovascular. Os diterpenos, em particular, estão entre os principais compostos associados às propriedades cardiovasculares, como a propriedade vasorrelaxante, inotrópica, diurética e a atividade hipotensora. Embora o mecanismo de vasorrelaxamento do manool seja visível, seu efeito sobre a pressão arterial (PA) ainda é desconhecido. Objetivo: Avaliar o efeito hipotensor in vivo do manool e verificar o efeito de vasorrelaxamento ex vivo em anéis aórticos de ratos. Métodos: Os animais foram divididos aleatoriamente em dois grupos: normotensos e hipertensos. O grupo normotenso foi submetido à cirurgia sham e adotou-se o modelo 2R1C para o grupo hipertenso. Realizou-se monitoramento invasivo da PA para testes com manool em diferentes doses (10, 20 e 40 mg/kg). Foram obtidas curvas de concentração-resposta para o manool nos anéis aórticos, com endotélio pré-contraído com fenilefrina (Phe) após incubação com Nω-nitro-L-arginina metil éster (L-NAME) ou oxadiazolo[4,3-a]quinoxalina-1-ona (ODQ). Os níveis plasmáticos de óxido nítrico (NOx) foram medidos por ensaio de quimioluminescência. Resultados: Após a administração de manool, a PA se reduziu nos grupos normotenso e hipertenso, e esse efeito foi inibido pelo L-NAME em animais hipertensos apenas na dose de 10 mg/kg. O manool ex vivo promoveu vasorrelaxamento, inibido pela incubação de L-NAME e ODQ ou remoção do endotélio. Os níveis plasmáticos de NOx aumentaram no grupo hipertenso após a administração de manool. O manool induz o relaxamento vascular dependente do endotélio na aorta de ratos, mediado pela via de sinalização NO/cGMP e redução da PA, e também pelo aumento plasmático de NOx. Esses efeitos combinados podem estar envolvidos na modulação da resistência periférica, contribuindo para o efeito anti-hipertensivo do diterpeno. Conclusão: Esses efeitos em conjunto podem estar envolvidos na modulação da resistência periférica, contribuindo para o efeito anti-hipertensivo do diterpeno.

Abstract Background: Many studies have shown that the diterpenoid classes exert a significant effect on the cardiovascular system. Diterpenes, in particular, are among the main compound links to cardiovascular properties such as vasorelaxant, inotropic, diuretic and hypotensive activity. While the manool vasorelaxation mechanism is visible, its effect on blood pressure (BP) is still unknown. Objective: To evaluate the in vivo hypotensive effect of manool and check the ex vivo vasorelaxation effect in rat aortic rings. Methods: The animals were divided randomly into two groups: normotensive and hypertensive. The normotensive group was sham-operated, and the 2K1C model was adopted for the hypertensive group. Invasive BP monitoring was performed for manool tests at different doses (10, 20 and 40 mg/kg). Concentration-response curves for manool were obtained in the aorta rings, with endothelium, pre-contracted with phenylephrine (Phe) after incubation with Nω-nitro-L-arginine methyl ester(L-NAME) or oxadiazole [4,3-a]quinoxalin-1-one (ODQ). Nitric oxide (NOx) plasma levels were measured by chemiluminescence assay. Results: After manool administration, BP was reduced in normotensive and hypertensive groups, and this effect was inhibited by L-NAME in hypertensive animals only in 10 mg/kg dose. Ex vivo manool promoted vasorelaxation, which was inhibited by L-NAME and ODQ incubation or endothelium removal. NOx plasma levels increased in the hypertensive group after manool administration. Manool elicits endothelium-dependent vascular relaxation in rat aorta mediated by the NO/cGMP signaling pathway and BP reduction, also by NOx plasma increase. These combined effects could be involved in modulating peripheral resistance, contributing to the antihypertensive effect of diterpene. Conclusion: These effects together could be involved in modulating peripheral resistance, contributing to the antihypertensive effect of diterpene.

Passive Cigarette Smoking Impact on Blood Pressure Response to Epinephrine and Felypressin in 1K1C Hypertensive Rats Treated or not with Atenolol / Impacto do Tabagismo Passivo na Resposta Pressórica à Epinefrina e Felipressina em Ratos Hipertensos 1K1C Tratados ou não com Atenolol

Abstract Background: Cigarette smoking is usually associated with hypertension and may modify vasoconstrictor response. Objective: The present study aimed to analyze and compare the interaction of passive cigarette smoking and hypertension on epinephrine and felypressin blood pressure effects after intravascular injection. Method: 45-day male Wistar rats had the main left renal artery partially constricted and the right kidney removed (1K1C model). Rats were placed in the chamber for exposition to passive cigarette smoking (10 cigarettes) during 10 min (6 days a week). Hypertensive rats received atenolol (90 mg/kg/day) by gavage for two weeks. Hypotensive and hypertensive response, response duration and heart rate were recorded from direct blood pressure values. The significance level was 5%. Results: Passive cigarette smoking increased maximal hypertensive response to epinephrine in normotensive and 1K1C-atenolol treated rats and to felypressin only in 1K1C-atenolol treated rats; it also reduced epinephrine hypotensive response. Epinephrine increased heart rate in normotensive and hypertensive passive smokers or non-smoker rats. Comparing the two vasoconstrictors, epinephrine showed greater hypertensive response in normotensive smokers, 1K1C-atenolol treated smokers and non-smokers. However, in normotensive-nonsmoker rats, felypressin showed a greater and longer hypertensive effect. Conclusions: Our results suggest that passive cigarette smoking may reduce epinephrine vasodilation and increase hypertensive response when compared to felypressin. Therefore, felypressin may be safe for hypertensive patients to avoid tachycardia and atenolol interaction, but for normotensive and non-smoker patients, epinephrine may be safer than felypressin.

Resumo Fundamento: O tabagismo geralmente está associado à hipertensão e pode modificar a resposta vasoconstritora. Objetivo: O presente estudo teve como objetivo analisar e comparar a interação do tabagismo passivo e hipertensão sobre os efeitos da epinefrina e felipressina na pressão arterial após injeção intravascular. Métodos: Ratos Wistar machos de 45 dias tiveram a artéria renal principal esquerda parcialmente obstruída e o rim direito removido (modelo 1K1C). Os ratos foram colocados na câmara para exposição ao tabagismo passivo (10 cigarros) durante 10 minutos (6 dias por semana). Ratos hipertensos receberam atenolol (90 mg/kg/dia) por gavagem durante duas semanas. A resposta hipotensora e hipertensiva, a duração da resposta e a frequência cardíaca foram registradas a partir da medida dos valores diretos da pressão arterial. O nível de significância foi de 5%. Resultados: O tabagismo passivo aumentou a resposta hipertensiva máxima à epinefrina em ratos normotensos e ratos 1K1C tratados com atenolol e à felipressina apenas em ratos 1K1C tratados com atenolol; também reduziu a resposta hipotensiva à epinefrina. A epinefrina aumentou a frequência cardíaca em ratos fumantes passivos ou não-fumantes, normotensos e hipertensos. Comparando os dois vasoconstritores, a epinefrina apresentou maior resposta hipertensiva em fumantes normotensos, ratos 1K1C fumantes e não fumantes tratados com atenolol. No entanto, em ratos normotensos e não fumantes, a felipressina apresentou um efeito hipertensivo maior e mais prolongado. Conclusões: Nossos resultados sugerem que o tabagismo passivo pode reduzir a vasodilatação da epinefrina e aumentar a resposta hipertensiva quando comparado à felipressina. Portanto, a felipressina pode ser segura para pacientes hipertensos, com o objetivo de evitar a interação entre taquicardia e atenolol, mas para pacientes normotensos e não-fumantes, a epinefrina pode ser mais segura que a felipressina.

Possible mechanisms involved in the effect of the subchronic administration of rosuvastatin on endothelial function in rats with metabolic syndrome

Metabolic syndrome is a multifaceted condition associated with a greater risk of various disorders (e.g., diabetes and heart disease). In a rat model of metabolic syndrome, an acute in vitro application of rosuvastatin causes relaxation of aortic rings. Since the outcome of a subchronic rosuvastatin treatment is unknown, the present study explored its effect on acetylcholine-induced vasorelaxation of aortic rings from rats with metabolic syndrome. Animals were submitted to a 16-week treatment, including a standard diet, a cafeteria-style diet (CAF-diet), or a CAF-diet with daily rosuvastatin treatment (10 mg/kg). After confirming the development of metabolic syndrome in rats, aortic segments were extracted from these animals (those treated with rosuvastatin and untreated) and the acetylcholine-induced relaxant effect on the corresponding rings was evaluated. Concentration-response curves were constructed for this effect in the presence/absence of L-NAME, ODQ, KT 5823, 4-aminopyridine (4-AP), tetraethylammonium (TEA), apamin plus charybdotoxin, glibenclamide, indomethacin, clotrimazole, and cycloheximide pretreatment. Compared to rings from control rats, acetylcholine-induced vasorelaxation decreased in rings from animals with metabolic syndrome, and was maintained at a normal level in animals with metabolic syndrome plus rosuvastatin treatment. The effect of rosuvastatin was inhibited by L-NAME, ODQ, KT 5823, TEA, apamin plus charybdotoxin, but unaffected by 4-AP, glibenclamide, indomethacin, clotrimazole, or cycloheximide. In conclusion, the subchronic administration of rosuvastatin to rats with metabolic syndrome improved the acetylcholine-induced relaxant response, involving stimulation of the NO/cGMP/PKG/Ca2+-activated K+ channel pathway.

Mild-intensity Exercise Triggers VEGF in the Digestive Tract Via Both Hypoxic and Nonhypoxic Mechanisms

Abstract Hypoxia occurs in the splanchnic region during exercise associated with sympathetic activity. In the elderly, vascular insufficiency and low vascular endothelial growth factor (VEGF) expression are observed. Compared to young people, sympathetic signals of older individuals are blunted and more resistant to splanchnic blood flow alterations during exercise. VEGF induces vasodilation responses and hence may retain blood in the splanchnic vascular bed. We hypothesized that regular mild-intensity exercise triggers weak VEGF expression in the digestive tract of the elderly. The effects of exercise on the levels of VEGF, superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA) and total antioxidant capacity (T-AOC) in the stomach, jejunum, ileum and colon tissues were evaluated. With exercise, the VEGF levels in the stomach and colon increased. Although the SOD, GPx, and MDA levels decreased in the stomach, they increased in the colon. T-AOC increased in the stomach and there was no change in the jejunum, ileum and colon. The hypoperfusion during exercise was not equal in all regions of the gastrointestinal tract in the aged subjects. Hypoxia and other exercise-related mechanisms could have led to this VEGF induction. The stomach, jejunum, and ileum might have developed resistance to ischemia. The induction of VEGF may be beneficial in aging-associated impaired gastrointestinal homeostasis and neovascularization.

Acute effects of strength exercise with blood flow restriction on the arterial resistance index / Efeitos agudos do exercício de força com restrição do fluxo sanguíneo sobre o índice de resistência arterial

ABSTRACT The present study aimed to evaluate the acute behavior of the brachial artery resistance index (BARI) and popliteal artery resistance index (PARI) in response to low intensity strength exercises involving small (SMG) and large muscle groups (LMG) performed with and without blood flow restriction. Eleven men (age 23 ± 3.29 years) underwent a four-arm, randomized, cross-over experiment: Small muscle group exercise (SMG), small muscle groups with blood flow restriction (SMG+BFR), large muscle groups (LMG) and large muscle groups with blood flow restriction (LMG+BFR). The behavior of BARI and PARI was evaluated at rest, immediately after exercise, and at 15 and 30 minutes during recovery. Data analysis showed a significant reduction of the BARI from rest to post-exercise only in the protocols involving SMG, regardless of the BFR (p <0.05). Protocols involving LMG, with or without BFR, did not affect PARI (p> 0.05), but were efficient to promote significant increases in BARI (p <0.05) immediately after exercise. Our findings indicate that the exercises involving SMG, regardless of BFR, are efficient to promote local vasodilatation (brachial artery), but without systemic effects. None of the analyzed protocols affected the PARI behavior.

RESUMO O presente estudo objetivou avaliar o comportamento agudo do índice de resistência da artéria braquial (IRAB) e da artéria poplítea (IRAP) em resposta a exercícios de força de baixa intensidade envolvendo pequenos (PGM) e grandes grupos musculares (GGM), realizado com e sem restrição de fluxo sanguíneo. Onze homens (idade 23 ± 3,29 anos) realizaram um experimento randomizado, cruzado, com quatro braços: Exercício para pequenos grupos musculares (PGM), pequenos grupos musculares com restrição de fluxo sanguíneo (PGM+RFS), grandes grupos musculares (GGM) e grandes grupos musculares com restrição de fluxo sanguíneo (GGM+RFS). O comportamento de IRAB e IRAP foi avaliado em repouso, mediatamente após o exercício, e aos 15 e 30 minutos da recuperação. A análise dos dados mostrou uma redução significativa do IRAB do repouso para o pós-exercício apenas nos protocolos de PGM com ou sem RFS (p <0,05). Protocolos envolvendo GGM, independentemente do BFR, não afetaram o IRAP (p> 0,05), porém, foram eficientes para promover aumentos significativos do IRAB (p <0,05) imediatamente após o exercício. Nossos achados indicam que os exercícios envolvendo PGM, independentemente da BFR, são capazes de promover a vasodilatação local (artéria braquial), porém, sem efeitos sistêmicos. Nenhum dos protocolos analisados afetou o comportamento do IRAP.

Interaction of genetic background and exercise training intensity on endothelial function in mouse aorta

The purpose of this study was to characterize the genetic contribution to endothelial adaptation to exercise training. Vasoreactivity was assessed in aortas from four inbred mouse strains (129S1, B6, NON, and SJL) after 4 weeks of moderate intensity continuous exercise training (MOD), high intensity interval training (HIT) or in sedentary controls (SED). Intrinsic variations in endothelium-dependent vasorelaxation (EDR) to acetylcholine (ACh) as well as vasocontractile responses were observed across SED groups. For responses to exercise training, there was a significant interaction between mouse strain and training intensity on EDR. Exercise training had no effect on EDR in aortas from 129S1 and B6 mice. In NON, EDR was improved in aortas from MOD and HIT compared with respective SED, accompanied by diminished responses to PE in those groups. Interestingly, EDR was impaired in aorta from SJL HIT compared with SED. The transcriptional activation of endothelial genes was also influenced by the interaction between mouse strain and training intensity. The number of genes altered by HIT was greater than MOD, and there was little overlap between genes altered by HIT and MOD. HIT was associated with gene pathways for inflammatory responses. NON MOD genes showed enrichment for vessel growth pathways. These findings indicate that exercise training has non-uniform effects on endothelial function and transcriptional activation of endothelial genes depending on the interaction between genetic background and training intensity.

Effects of in vitro amitriptyline, fluoxetine, tranylcypromine and venlafaxine on saphenous vein grafts

Abstract Objective: In this study, we aimed to examine the effects of amitriptyline, fluoxetine, tranylcypromine and venlafaxine on saphenous vein grafts in coronary artery bypass graft surgeries. Methods: 59 patients (40 males and 19 females; mean age 65.1 years, distribution: 45-84 years) who had coronary artery bypass graft surgery between February 2014 and May 2016 were included in the study. After the saphenous vein grafts with intact and denuded endothelium were precontracted with 3×10-6M phenylephrine, amitriptyline, fluoxetine and tranylcypromine were cumulatively added to isolated organ baths in the range of 10-11-3x10-5M, while venlafaxine was added in the range of 10-9-3×10-5M. Then, the antidepressant-induced relaxation responses were recorded isometrically. Results: While the relaxation response of amitriptyline at -6.42 (Log M) was 74.6%, the response at -6.32 (Log M) was 75.5%. While the relaxation response at -6.46 (Log M) of fluoxetine was 68.02%, the response at -6.02 (Log M) was 72.12%. While the relaxation response of tranylcypromine at -7.53 (Log M) was 61.13%, the response at -7.23 (Log M) was 65.53%. While the relaxation response of venlafaxine at -6.21 (Log M) was 29.98%, the response at -5.90 (Log M) was 32.96%. Conclusion: The maximum relaxation at minimum and maximum therapeutic concentrations was obtained with amitriptyline, fluoxetine and tranylcypromine, and the minimum relaxation was obtained with venlafaxine. The relaxation responses were independent of the endothelium.

Antioxidant and Vasodilatory Action of Grape Juices Produced in Different Regions of Brazil

Grapes and its derivatives (wines and juices) are rich in polyphenols that have high antioxidant and vasodilator capacity. These biological activities may vary in the juices marketed and produced in different regions of Brazil. Objectives: To determine the antioxidant and vasorelaxant effects of grape juice samples produced in different regions of Brazil. Methods: The content of phenolic compounds and antioxidant capacity were evaluated by the methods of Folin-Ciocalteau, DPPH, ABTS and a new electroanalytical approach (differential pulse voltammetry - DPV). Vasodilator effects were analyzed in isolated aorta from rats in an organ bath. Results: The samples from RJ and SP presented respectively the higher and lower phenolic content and also antioxidant capacity by the methods used (ABTS and DPPH). The results of the electrochemical index corroborate to the other tests, with the best results to RJ (21.69 ± 3.15 µA/V) and worse to the SP sample (11.30 ± 0.52 µA/V). In the vascular reactivity studies, the relaxation induced by each sample presented more distinct differences, following the order: RJ (87.9 ± 4.8%) > RS1 (71.6 ± 8.6%) > GO (56.2 ± 7.2%) > SP (39.9 ± 7.8%) > PR (39.4 ± 9.5%) > RS2 (19.5 ± 6.2%). Inhibition of endothelial NO practically abolished (p < 0.001) the relaxation for all samples, except one. Conclusion: The phenolic content and antioxidant capacity vary greatly among samples. The results obtained for the order of antioxidant activity were: RJ > RS1 > GO > RS2 > PR > SP. The juices were able to induce vascular relaxation at quite varied levels, and the RJ sample the most effective. The L-NAME practically blocked all samples except one (RS2)

Participation of NO in the vasodilatory action of isoespintanol / Participación de NO en la acción vasodilatadora del isoespintanol

Background: accumulating evidence suggests that natural compounds and specifically monoterpenes exert a vasodilator action. Objetive: to investigate the vascular effects of isoespintanol (2-isopropil-3,6-dimetoxi-5-metilfenol, ISO) monoterpene isolated from the leaves of Oxandra cf xylopioides. Methods: thoracic aortic rings isolated from Wistar rats were contracted with KCl 80 mM and then relaxed by exposure to Ca2+-free solution in absence and in presence of ISO 0.6 mg/mL. The force/tissue ratio (F/W) and the time to obtain 50% of relaxation (T-50) were used to assess the maximal contractile response and the relaxation, respectively. To examine the participation of NO additional experiments were performed under inhibition of nitric oxide synthase with L-NAME (L-NG-Nitroarginine methyl ester). Results: ISO significantly decreased the F/W ratio (257 ± 19 vs. 360 ± 18) and did not change T-50. In presence of L-NAME the effects of ISO on contractile response was abolished. Conclusions: these results demonstrate that ISO exerts a vasodilator effect through NO-dependent pathways and suggest that an inhibition of calcium influx could be the involved mechanism

Antecedentes: la evidencia acumulada sugiere que los compuestos naturales, especialmente monoterpenos, ejercen una acción vasodilatadora. Objetivo: investigar los efectos vasculares del monoterpeno isoespintanol (2-isopropil-3,6-dimetoxi-5-metilfenol, ISO) aislado de hojas de Oxandra cf xylopioides. Métodos: anillos de aorta torácica aislados de ratas Wistar fueron contraídas con cloruro de potasio 80 mM y luego relajadas por exposición a una solución libre de Ca2+ en ausencia y presencia de isoespintanol 0,6 µg/mL. El radio fuerza/tejido (F/T) y el tiempo para obtener 50% de relajación (T50) se usaron para lograr la máxima respuesta contráctil y de relajación, respectivamente. Para evaluar la participación del óxido nítrico, se realizaron experimentos adicionales bajo la inhibición de la óxido nítrico sintetasa con L-NAME (L-NG-éster metílico de nitroarginina). Resultados: Isoespintanol disminuyó el radio F/W significativamente (257 ± 19 vs. 360 ± 18) y no cambió T-50. En presencia de L-NAME, los efectos del isoespintanol en la respuesta contráctil fueron suprimidos. Conclusiones: Estos resultados demuestran que el isoespintanol ejerce un efecto vasodilatador a través de vías NO dependientes y sugiere que la inhibición de la entrada de calcio puede ser el mecanismo involucrado.

The alterations of microvasculature, tyrosine phosphorylation, and lipid peroxidation in kidney of rats treated with valproic acid / Alteraciones de la microvasculatura, fosforilación de tirosina y peroxidación lipídica en riñones de ratas tratadas con ácido valproico

SUMMARY: Valproic acid (VPA), an antiepileptic drug, has been demonstrated to damage histology and to change tyrosine phosphorylation patterns with increased oxidative stress in perirenal tissues. This study aimed to investigate the effect of VPA on microstructure, tyrosine phosphorylation, and lipid peroxidation of rat kidney. Adult male rats were divided into control and VPA-treated groups intraperitoneally injected with normal saline and VPA 500 mg/kgBW for 10 consecutive days, respectively (n = 7 each). The blood serum was examined for biochemical levels. The kidney tissues were routinely processed for histological observation. Total proteins from kidney were extracted to assay the malondialdehyde (MDA) levels and phosphorylation expression. The results showed that VPA significantly decreased blood glucose levels while tend to increase urea nitrogen and creatinine. MDA levels in VPA group were significantly higher that of control. Renal cortex of VPA-treated animals revealed vasodilatations. Although the ratio of a renal phosphorylated 72 kDa protein/ beta actin expression seemed to be not different in both groups, VPA significantly decreased the intensity of beta actin. In conclusion, VPA dilates renal microvasculature with increasing of MDA but suppresses the actin expression.

RESUMEN: Se ha demostrado que el ácido valproico (AVP), un fármaco antiepiléptico, daña la histología y cambia los patrones de fosforilación de la tirosina con el aumento del estrés oxidativo en los tejidos perirrenales. Este estudio tuvo como objetivo investigar el efecto del AVP en la microestructura, la fosforilación de la tirosina y la peroxidación lipídica del riñón de rata. Se dividieron ratas macho adultas en grupos control y tratados con AVP. Durante 10 días consecutivos fueron inyectadas por vía intraperitoneal con solución salina normal y 500 mg / kg de PC respectivamente (n = 7 cada uno). Se analizó el suero sanguíneo para determinar los niveles bioquímicos. Los tejidos renales se procesaron de forma rutinaria para la observación histológica. Las proteínas totales del riñón se extrajeron para analizar los niveles de malondialdehído (MDA) y la expresión de la fosforilación. Los resultados mostraron que el AVP disminuyó significativamente los niveles de glucosa en la sangre, mientras que tienden a aumentar el nitrógeno ureico y la creatinina. Los niveles de MDA en el grupo de AVP fueron significativamente más altos que los del control. La corteza renal de los animales tratados con AVP reveló vasodilataciones. Aunque la proporción de una expresión de proteína / actina de 72 kDa fosforilada renal no parece ser diferente en ambos grupos, el AVP disminuyó significativamente la intensidad de la actina beta. En conclusión, el AVP dilata la microvasculatura renal al aumentar el MDA, pero suprime la expresión de actina.

Research advances in relationship between biological clock and cardiovascular diseases / 生理学报

Circadian rhythms widely exist in living organisms, and they are regulated by the biological clock. Growing evidence has shown that circadian rhythms are tightly related to the physiological function of the cardiovascular system, including blood pressure, heart rate, metabolism of cardiomyocytes, function of endothelial cells, and vasoconstriction and vasodilation. In addition, disruption of circadian rhythms has been considered as one of the important risk factors for cardiovascular diseases, such as myocardial infarction. This review summarizes the recent research advances in the relationship between circadian clock and cardiovascular diseases, hoping to improve treatment strategies for patients with cardiovascular diseases according to the theory of biological clock.

Power Doppler ultrasound-guided sialography using the phenomenon of increased blood flow: A technical report

PURPOSE: This report presents a procedure for performing power Doppler ultrasound-guided sialography using the phenomenon of increased blood flow and illustrates its application to practical patient cases.MATERIALS AND METHODS: The salivary gland was scanned using ultrasound equipment (GE LOGIQ5 Expert® device; GE Medical Systems, Milwaukee, WI, USA) to identify pathological findings related to the patient's chief complaint. To identify the orifice of the main duct, it should be cannulated using a lacrimal dilator. After inserting the catheter into the cannulated main duct, the position of the catheter within the duct was confirmed by ultrasound. A contrast agent was injected until the patient felt fullness, and ultrasound (B-mode) was used to confirm whether the contrast agent filled the main canal and secondary and tertiary ducts. Then, power Doppler ultrasound was performed to determine whether the salivary gland had increased blood flow.RESULTS: In 2 cases in this report, a power Doppler ultrasound scan showed a significant increase in blood flow after contrast medium injection, which was not observed on a preoperative scan.CONCLUSION: Power Doppler ultrasound was found to be a simple, safe, and effective tool for real-time sialography monitoring.