Electrocardiographic Abnormalities in Hypertension Models

Abstract Background: Hypertensive condition can lead to abnormalities in heart structure and electrical activity. The electrocardiogram (ECG) is a recording of the electrical activity of the heart and widely used to diagnose and detect heart problem. Objective: We conducted a comparative ECG analysis between two hypertension models (L-NAME and SHR) and their controls (Wistar and Wistar-Kyoto) at six and 15 th week of age. Methods: Blood pressure was measured at the end of the 15 th week, and electrocardiography was performed at six and 15 weeks of age in anaesthetized rats. Data normality was confirmed by Kolmogorov-Smirnov test followed by unpaired Student's t-test and the Mann-Whitney for parametric and non-parametric data, respectively. Results are expressed as mean ± SD. The accepted level of significance was set at p < 0.05. Results: L-NAME exhibited prolongation of JT and QT intervals and SHR showed a decrease in heart rate when compared to Wistar-Kyoto and L-NAME. Wistar-Kyoto exhibited short PR interval with increased QRS complex, and only QT prolongation at 15 weeks compared to Wistar. Conclusions: All the hypertension models used in this study featured an increase in blood pressure. However, while SHR showed cardiac dysfunction, L-NAME exhibited changes in ventricular performance. These results may guide future studies on different types and models of hypertension.

Imunomarcação para TRAP em tecido de reparação óssea de ratos espontaneamente hipertensos (SHR) tratados com Atenolol / Immunostaining for TRAP in bone healing tissue of Spontaneously Hypertensive Rats (SHR) treated with Atenolol

Introdução: A hipertensão arterial tem sido um dos maiores problemas de saúde no mundo, com grandes alterações para as doenças cardiovasculares e renais. O tecido ósseo tem função importante no suporte, proteção e locomoção e está sob o controle de fatores sistêmicos como hormônios e fatores locais, entre eles os fatores de crescimento e citocinas. A Fosfatase Ácida Tartarato Resistente (TRAP) é uma enzima que faz parte da família das fosfatases ácidas e apresenta localização intracelular; mais especificamente dentro do compartimento lisossomal de osteoclasto, macrófagos e células dendríticas, tem sido utilizada como um marcador histoquímico da atividade osteoclástica. Objetivos: Avaliar a expressão da proteína TRAP em alvéolos dentários de ratos hipertensos (SHR) e normotensos tratados ou não com atenolol. Métodos: Neste estudo foram utilizados 4 grupos de ratos sendo: 1) W (wistar sem tratamento), 2) WT (wistar tratado com atenolol), 3) S (SHR sem tratamento) e 4) ST (SHR tratado com atenolol), submetidos a exodontia do incisivo superior direito, com eutanásia no 7º, 14º, 21 e 28º dia pós-operatório. A análise dos mecanismos biológicos envolvidos no processo de reparo alveolar foi obtida pela análise da expressão de proteínas TRAP por meio da técnica de imunoistoquímica. Os resultados foram analisados pela média e erro padrão da média e aplicado o teste paramétrico ANOVA, com pos-test de Tukey para avaliar os períodos dentro de cada grupo e entre os grupos, sendo consideradas as diferenças significativas quando p<0,05. Resultados: Os resultados mostraram que a marcação TRAP aumenta em alvéolo dentais de ratos Wistar durante todos os períodos pós ­ operatórios. A marcação TRAP aumenta apenas ao 14o nos dias de reparação alveolar em alvéolo dental de SHR não tratados. O atenolol não altera o processo de reparo alveolar em ratos Wistar, porém o atenolol promoveu a redução da marcação de TRAP em SHR ao 14º dia. Conclusão: A hipertensão aumenta a expressão da proteína TRAP no 14o dia pós-cirúrgico de reparação alveolar e o atenolol promove redução da marcação aumentada de TRAP ao 14º dia pós-cirúrgico em alvéolos de SHR(AU)

Introduction: Arterial hypertension has been one of the world's biggest health problems, with considerable alterations for cardiovascular and renal diseases. The bone tissue has an important role in support, protection and locomotion and is controlled by systemic factors like hormones and local factors, such as growth factors and cytokines. The Tartrate-resistant Acid Phosphatase (TRAP) is an enzyme that belongs to the Acid Phosphatases family and has an intracellular location, more specifically inside the lysosomal compartment of osteoclasts, macrophages and dendritic cells. It has been used as a histochemical marker of the osteoclast activity. Objectives: Evaluate TRAP protein's expression in the dental alveoli of normotensive and hypertensive rats (SHR) treated or not treated with Atenolol. Methods: In this study, four groups of rats were used: 1) W (with no treatment), 2) WT (wistar treated with Atenolol), 3) S (SHR without treatment) and 4) ST (SHR treated with Atenolol), all of which underwent exodontia of the upper right incisor with euthanasia on the 7th, 14th, 21st and 28th day after the operation. The analysis of the biological mechanisms involved in the process of alveolar repair was obtained by the expression of TRAP proteins in the alveolar process through an immunohistochemistry technique. The results were analyzed through the average and its standard error. The parametric test ANOVA was applied with Tukey's posttest were applied to evaluate the periods within each group and between the groups, considering the significant differences when p< 0,05. Results: The results demonstrated that TRAP staining increases in the dental alveoli of Wistar rats during all the post-surgical periods. TRAP staining increases only on the 14th day of alveolar recovery in the dental alveoli of non-treated SHR. Atenolol does not change the process of alveolar repair in Wistar rats, but Atenolol promoted the reduction of TRAP staining among SHR on the 14th day. Conclusion: Hypertension increases the expression of TRAP proteins on the 14th alveolar recovery postsurgical day and Atenolol promotes the reduction of the increased TRAP staining on the 14th postsurgical day in SHR's alveoli(AU)

Effect of Intravenous Infusion of Vasostatin-2 on Hemodynamics in Experimental Rats With Spontaneous Hypertension / 中国循环杂志

Objective: To observe the effect of the intravenous infusion of vasostatin-2 (VS-2) on hemodynamics in experimental rats with spontaneous hypertension (SH). Methods: A total of 36 (14-16) weeks male SH rats with the mean body weight at (160-250) g were randomly divided into 6 groups:①Control group, the rats received normal saline (100μl/kg),②Catestatin (20μg/kg) group,③VS-2 (5μg/kg) group,④VS-2 (10μg/kg) group,⑤VS-2 (20μg/kg) group and⑥VS-2 (40μg/kg) group. n=6 in each group. The average blood pressure (BP), heart rate (HR) and barorelfex sensitivity (BRS) were monitored and compared upon VS-2 treatment and between VS-2 and catestatin treatments in conscious and freelance rats. Results: Compared with prior treatment, VS-2 (20μg/kg) and VS-2 (40μg/kg) could obviously decrease the HR, BP and BRS in SH rats. In VS-2 (20μg/kg) group, HR by bpm was (341.3 ± 19.3) vs (365.5 ± 25.5), BP by mmHg was (133.0 ± 8.9) vs (147.5 ± 11.2) and BRS by ms/mmHg was (0.52 ± 0.18) vs (0.37 ± 0.12);in VS-2 (40μg/kg) group, HR was (348.8 ± 30.8) vs (374.5 ± 34.8), BP was (131.5 ± 9.3) vs (151.7 ± 10.8) and BRS was (0.53 ± 0.05) vs (0.38 ± 0.03), all P0.05. Conclusion: Intravenous infusion of VS-2 may obviously affect HR, BP and BRS in experimental SH rats;compared with the same dosage of catestatin, VS-2 had the weaker reduction of HR, BP and BRS.

Effect of Angelica Sinensis Volatile Oil on miRNA differential expression profiling in myocardium tissue in spontaneously hypertensive rats / 吉林大学学报(医学版)

Objective:To explore the effect of Angelica Sinensis Volatile Oil on the mi RNA expression profiling in myocardium tissue of the spontaneously hypertensive rats (SHRs),and to clarify the possible mechanism of Angelica Sinensis Volatile Oil.Methods:All the SHRs were divided into Angelica group,model group and captopril group,and other Wistar rats with the same age were selected as control group.The non-invasive systolic blood pressure was detected;after 4 weeks of administration,the changes of miRNA expression profiling in myocardium tissue were measured by Affymetrix miRNA 4.0 Array.KEGG analysis was used to identify the target genes. Results:Compared with control group,the systolic blood pressure of the rats in model group was significantly decreased (P < 0.05)before treatment.4 weeks after administration,compared with model group,the systolic blood pressure of the rats in Angelica group was significantly decreased (P <0.05).Compared with model group, 29 differential miRNAs of rats in Angelica group were found (P < 0.05 ), with 13 up-regulated miRNAs and 16 down-regulated miRNAs.The KEGG analysis results showed that miR-19a,let-7i,and miR-181c were related to insulin signaling pathways; let-7i, miR-181a, and miR-455 were related to VEGF signaling pathways;miR-122,miR-181a, miR-200b, miR-181c, let-7i, and miR-19a were related to apoptosis (P < 0.05 ). Conclusion:Angelica Sinensis Volatile Oil can decrease the blood pressure in SHRs and it can regulate the blood pressure by regulating the miRNA related to insulin signaling pathways and VEGF signaling pathways.

Antihypertension and cardio-protective effect of Zusanli and Taichong in spontaneously ;hypertensive rats / 国际中医中药杂志

Objective This study aims to explore antihypertension and heart protective effect of acupuncture on SHR rats through the observation of blood pressure, cardiac ultrasound and pathology examination of SHR rats after needling the Zusanli (ST 36) and Taichong (LR 3). Methods A total of 14 SHR rats (10 weeks) were randomly divided into two groups:6 for model group and 8 for acupuncture group, another 6 SD rats (10 weeks) were used as the control group. SHR rats in the acupuncture group were fixed in the holder, and then they exposed both lower limbs for needling both sides Zusanli (ST 36) and Taichong (LR 3), and then they retained needles for 20 minutes per time with four weeks. The other two groups were fixed in the holder without needling. Blood pressure was examined each week. LVSs, LVDd, LVPWs, LVPWd were measured and recorded by cardiac ultrasound in the day after the whole course of acupuncture. LVM, LVMI, RWT were calculated. The hearts of rats were dissected and fixed in formalin for heart pathology detection after doing the cardiac ultrasound. Results After acupuncture treatment, compared with model group, the systolic blood pressure (SBP) of the third week (178.38 ± 9.47 mmHg vs. 190.00 ± 13.90 mmHg) and the fourth week (167.96 ± 23.47 mmHg vs. 195.47 ± 11.36 mmHg) of acupuncture group significantly decreased (P<0.01). The diastolic pressure (DBP) of the third week (139.33 ± 13.20 mmHg vs. 159.56 ± 12.89 mmHg) and the fourth week (132.92 ± 18.02 mmHg vs. 165.61 ± 13.36 mmHg) of acupuncture group significantly decreased (P<0.01). The LVSs (0.96 ± 0.07 vs. 1.28 ± 0.24), LVPWs (1.15 ± 0.08 vs. 1.68 ± 0.19) of the acupuncture group were significantly lower than those of the model group (P<0.01). The LVM (0.51 ± 0.12 vs. 0.84 ± 0.17) and LVMI (14.96 ± 1.53 vs. 23.65 ± 5.04) of acupuncture group were significantly lower than those of the model group (P<0.01). Histopathologic examination of the heart of the model group showed chronic inflammatory granulation tissue hyperplasia and fibrosis in myocardial outer membrane, but the acupuncture group showed no obvious changes in the heart tissue. Conclusions Acupuncture treatment on Zusanli (ST 36) and Taichong (LR 3) could effectively control the left ventricular hypertrophy by decreasing the SBP and DBP , prevent cardiac remodeling, and protect myocardial cells.

Effects of Fosinopril on Oxidative Stress and Vascular Function in Experimental Rats With Spontaneous Hypertension / 中国循环杂志

Objective: To explore the effects of fosinopril on oxidative stress and vascular function in experimental rats with spontaneous hypertension. Methods: The rats were divided into 3 groups: Control group, with normal healthy rats (n=15), Spontaneous hypertension (SH) group (n=15), SH rats received intragastric administration of normal saline and Treatment group (n=15), SH rats received intragastric administration of fosinopril 10mg/(kg?d). All animals were treated for 7 weeks. Caudal artery systolic blood pressure (SBP) was measured at each week. blood levels of superoxide dismutase (SOD), reactive oxygen species (ROS), malonaldehyde (MDA) and NO2-/NO3- were determined in different groups respectively after 7 weeks. Moreover, thoracic aorta was taken to examine its diastolic reactive rate by acetylcholine (Ach)/sodium nitroprusside (SNP) induction. Results: From the 1st week until the end of experiment, compared with SH group, Treatment group had decreased SBP,P<0.05. With 7 weeks treatment, compared with Control group, SH group had decreased SOD activity, while increased protein levels of MDA and ROS, allP<0.05; compared with SH group, Treatment group showed elevated SOD activity (P=0.010), while reduced protein levels of MDA (P=0.021) and ROS (P=0.009). Compared with Control group, SH group had the lower content of NO2-/NO3-(P<0.001); both SH group and Treatment group had decreased diastolic rates by Ach/SNP induction,P<0.05. Compared with SH group, Treatment group presented the higher content of NO2-/NO3- and higher diastolic rate by Ach induction, allP<0.001. Conclusion: Fosinopril could improve vascular diastolic function via anti-oxidative stress in experimental SH rats, which might be one of its anti-hypertensive mechanisms.

Efeito vasorelaxante do doador de óxido nítrico [Ru(terpy)(bdq)NO]3+ (TERPY) em artéria de resistência e sua interação com a óxido nítrico sintase endotelial (eNOS) de Ratos Espontaneamente Hipertensos (SHR) / Vasorelaxation effect of nitric oxide donor [Ru(terpy)(bdq)NO]3+ (TERPY) on resistance artery and its interaction with endothelial nitric oxide synthase (eNOS) of Spontaneously Hypertensive Rats (SHR)

O TERPY promove efeito hipotensor de maior magnitude em ratos hipertensos (SHR e 2R-1C) do que em ratos normotensos (Wistar e 2R). Foi demonstrado anteriormente que o endotélio prejudica o efeito vasodilatador do TERPY em aorta de Wistar. No entanto, observamos que o endotélio melhora os efeitos vasodilatadores do TERPY em aorta de SHR. Vasos sanguíneos de menor calibre, tais como as artérias de resistência, estão associadas ao controle da resitência vascular periférica e da pressão arterial. Nossa hipótese é que o TERPY induz relaxamento nas artérias mesentéricas de resistência em SHR e que as células endoteliais modulam positivamente o efeito do TERPY nestes vasos sanguíneos. Portanto, o nosso objetivo foi avaliar o efeito vasodilatador do TERPY em anéis com e sem endotélio de artéria mesentérica de ratos SHR, o seu mecanismo de relaxamento e a participação da NOS sobre esse efeito. e a Nossos resultados mostraram que o TERPY induziu um efeito vasodilatador dependente da concentração em anéis de artérias mesentéricas (2º e 3º ramos) de SHR e de ratos Wistar. A potência do TERPY foi maior em anéis intactos do que em anéis sem endotélio em artérias mesentéricas de SHR, mas em Wistar o endotélio prejudicou o efeito do TERPY. Nas artérias mesentéricas sem endotélio de SHR, o efeito do TERPY é dependente da atividade da guanilato ciclase solúvel e de canais para potássio. Nas artérias mesentéricas intactas de SHR, o efeito de TERPY depende da atividade de eNOS, mas não é dependente das atividades de nNOS, iNOS ou da via da ciclooxigenase. O TERPY promove a fosforilação da eNOS nos resíduos de serina1177 e aumenta a concentração de óxido nítrico em células endoteliais isoladas de artérias mesentéricas de SHR. Nossos resultados mostraram que a guanilato ciclase solúvel, os canais para potássio e a eNOS estão envolvidos no efeito vasodilatador estimulado pelo TERPY nas artérias de resistência mesentérica de SHR. Numa segunda parte deste estudo, avaliamos o mecanismo de ação de TERPY e seu efeito sobre a atividade da eNOS em células endoteliais. As células HUVEC, WT-HEK e HEK-eNOS foram tratadas com TERPY em diferentes tempos (0 a 60 minutos). Foram analisados por Western blotting o efeito do TERPY sobre a fosforilação de eNOS, monômero e dímero da eNOS e sobre monômero e oligômero de caveolina-1. Também foi avaliado o efeito do TERPY na interação eNOS/Cav-1 através de co-imunoprecipitação. As alterações induzidas pelo TERPY sobre as concentrações de espécies reativas de oxigênio e peroxinitrito em células endoteliais foram medidas usando sonda DHE e biossensor 7-CBA, respectivamente. A concentração de óxido nítrico (NO) foi avaliada por sonda DAF-FM e sensor Cooper. O TERPY promoveu desacoplamento e disfunção da eNOS, dependente de BH4. A desestabilização dos oligômeros da caveolina-1 foi induzida pelo TERPY. Consequentemente, o TERPY reduziu a interação eNOS/Cav-1 e promoveu ativação da eNOS. Nossos resultados mostraram que a atividade da eNOS pode ser regulada de duas maneiras diferentes pelo TERPY. O TERPY promove desacoplamento e fosforilação da eNOS, promovendo uma estratégia diferente para a regulação da atividade desta enzima. As moléculas químicas ou biológicas como o TERPY que regulam a atividade da eNOS e aumentam a produção e a biodisponibilidade de NO teriam ações terapêuticas importantes para o tratamento de doenças vasculares associadas a hipertensão(AU)

TERPY promotes a hypotensive effect with greater magnitude in hypertensive rats (SHR and 2K-1C) than in normotensive rats (Wistar and 2K). Previously, it was demonstrated that endothelium impairs vasodilatory effect of TERPY in Wistar aorta. However, we observed that endothelium improves the vasodilatory effect of TERPY in SHR aorta. Smaller blood vessels, such as mesenteric arteries, are associated with the control of peripheral vascular resistance and blood pressure. We hypothesized that TERPY induces relaxation on mesenteric resistance arteries in SHR and endothelial cells modulate positively the TERPY's effect on these blood vessels. Therefore, our goal was to evaluate the vasodilator effect of TERPY in rings with and without endothelium of mesenteric arteries in SHR, the mechanism of relaxation and the participation of NOS on this effect. Our results show TERPY induced a concentration-dependent vasodilator effect in mesenteric arteries (2nd and 3 rd branches) rings from SHR and Wistar. The potency of TERPY was higher in intact than in denuded rings from SHR, but in Wistar, endothelium impair the TERPY's effect. In denuded mesenteric arteries from SHR, the relaxation effect induced by TERPY is dependent of soluble guanylate cyclase and activation of potassium channel. However, in intact mesenteric arteries from SHR, TERPY´s effect is modulated by eNOS activity, but it is not dependent of nNOS, iNOS or cyclooxygenase pathway activities. TERPY promotes eNOS3 Ser1177 phosphorylation and increases nitric oxide concentration in isolated endothelial cells of mesenteric arteries from SHR. Together, our results showed that soluble guanylate cyclase, potassium channels, and eNOS are involved in the vasodilator effect of TERPY in mesenteric resistance arteries from SHR. In a second part of this study, we aimed to evaluate the mechanism of action of TERPY and its effect on eNOS activity in endothelial cells. HUVEC, WT-HEK and HEK-eNOS cells were treated with TERPY at different times (0 to 60 minutes). Were analyzed by western blotting the TERPY`s effect on eNOS monomer, dimer and phosphorylation and on monomer and oligomer of caveolin-1. It was also evaluated the effect of TERPY in the interaction between eNOS/Cav-1 through co-immunoprecipitation. Alterations induced by TERPY on reactive oxygen species and peroxynitrite concentrations in endothelial cells were measured by using DHE probe and biosensor 7-CBA, respectively. Nitric oxide fluorescence was assessed by DAF-FM probe and Cooper sensor. TERPY promoted eNOS uncoupling and eNOS dysfunction, which is BH4-dependent. Caveolin-1 oligomers destabilization was induced by TERPY. Consequently, TERPY reduced eNOS/Cav-1 interaction and promoted eNOS activation. Our results show that eNOS activity can be regulated in two different ways by TERPY, leading to eNOS uncoupling and leading to eNOS phosphorylation, promoting a strategy for eNOS regulation. Chemical or biological molecules as TERPY that regulates eNOS activity and increase NO production and bioavailability are potential therapeutic drugs for the treatment of vascular diseases associated with hypertension(AU)

Microarray Analysis in Spontaneously Hypertensive Rat Heart after Losartan Treatment / 이화의대지

OBJECTIVES: Spontaneously hypertensive rats (SHR) are frequently used as rat models of essential hypertension. The mechanism for the development of hypertension is complicated and it is unknown. The renin-angiotensin system (RAS) plays a key role in the control of blood pressure. Microarrays are a powerful tool for studying genetics. The purpose of this study was to investigate changes of gene expression in the heart tissues of SHR after losartan treatment to provide basic data that is useful in the early diagnosis of hypertension and gene treatment. METHODS: Rats were divided into three groups: the control (C) group; the hypertension (H) group (SHR), and the losartan (L) group; treated with losartan (10 mg/kg/day) in SHR. Rats were sacrificed at week 5 and microarray analysis was performed. RESULTS: 102 gene expressions including the genes associated with cell proliferation such as Raf1, Uchl1, Btla, Spock1 were increased. The other 139 gene expressions, including the genes related to the regulation of metabolism such as TFIID, Auf1, Bmp, Hub, Taf51 showed decreases in gene expression. A total of 31 genes were differentially expressed in the L group compared to the H group. Of these, 16 genes including the genes associated with macromolecule metabolism such as MGC105766, Ppp1r1a, Rpl3l showed increased expression. The other 15 genes including the genes associated with primary metabolism such as Mcpt4, Ngn3, Tdo, Ak2 Hyal2 showed decreased expressions. CONCLUSION: According to microarray analysis, there was significant gene expression change in SHR compared with normal rats as well as significant gene expression changes after losartan treatment in SHR.

Effect of exercise on the maternal outcome in pregnancy of spontaneously hypertensive rats

PURPOSE: To evaluate the effect of exercise (swimming) on pregnancy in spontaneously hypertensive rats (SHR). METHODS: Thirty three pregnant female SHR were distributed into three groups (n=11 animals/group): SHR Control=non-exercised (sedentary); SHR Ex0 = exercised from day zero to day 20 of pregnancy; and SHR Ex7 = exercised from day 7 to 20 of pregnancy. Body weight and systolic blood pressure were indirectly measured during pregnancy. On gestational day 21, the rats were anaesthetized and uterine content was withdrawn for analysis of maternal reproductive outcome parameters and fetal development. RESULTS: The reduced blood pressure percentage was higher in SHR Ex0 and SHR Ex7 compared to SHR Control group. Weight gain was present in all pregnancy periods, but it was lower in SHR Ex7 than in SHR Control dams. The exercise increased the pre-implantation loss rate. The post-implantation loss rate was lower in SHR Ex0 group. SHR Ex7 group showed a significantly higher percentage of fetuses classified as small for gestational age as compared to others groups. CONCLUSION: The exercise contributed to lowering gestational blood pressure in SHR rats, but had a negative impact on the developing embryo. .

Efeito do exercício físico e suplementação de potássio sobre a pressão arterial, metabolismo glicídico e albuminúria de ratos hipertensos / Effects of physical training and potassium supplementation on blood pressure, glucose metabolism and albuminuria of spontaneously hypertensive rats

Introdução: Ainda é controverso se ocorre sinergismo entre as diferentes medidas não farmacológicas utilizadas no tratamento da hipertensão arterial. Objetivo: Avaliar o efeito do exercício físico aeróbico, da sobrecarga oral de potássio e da sua associação sobre a pressão arterial, metabolismo glicídico, excreção urinária de albumina e morfologia glomerular de ratos espontaneamente hipertensos (SHR). Métodos: SHRs foram divididos em: Grupo Controle (SHR; dieta padrão e sedentário, n = 10); Grupo Exercício (SHR + E; treinado em esteira rolante, dieta padrão, n = 10), Grupo Potássio (SHR + K; sedentário, dieta rica em potássio, n = 10) e Grupo Exercício + Potássio (SHR + E + K; exercitado, dieta rica em potássio, n = 10). Semanalmente, foi aferido o peso corporal (PC) e a pressão arterial de cauda (PAC). Ao final de 16 semanas, foi realizado o Teste de Tolerância oral a Glicose. A albuminúria foi determinada nos períodos basal, na 8ª e 16ª semana. Após o sacrifício, foi realizada a análise do índice de esclerose glomerular e a pesagem da gordura visceral. Resultados: A PAC e o PC não variaram significativamente. Houve melhora da sensibilidade à insulina no Grupo Exercício e Grupo Potássio, mas não no Grupo Exercício + Potássio. Na 16ª semana, a albuminúria de todos os grupos foi significativamente menor que o grupo SHR Controle. O índice de esclerose glomerular e o peso da gordura visceral também foram significativamente menores em todos os grupos tratados quando comparados ao controle. Conclusão: A dieta rica em potássio e o exercício físico determinaram melhora no metabolismo glicídico, na albuminúria e na morfologia glomerular, porém, a sobreposição ...

Introduction: It is still controversial whether there are synergistic effects among different non-pharmacological interventions used in the treatment of hypertension. Objetives: To evaluate the effect of aerobic exercise, oral supplementation of potassium and their combination on blood pressure, glucose metabolism, urinary albumin excretion and glomerular morphology in spontaneously hypertensive rats (SHR). Methods: SHR were divided into groups: Control Group (SHR; standard diet and sedentary, n = 10), Exercise Group (SHR + E; trained on a treadmill, standard diet, n = 10), Potassium Group (SHR + K; sedentary, potassium supplementation, n = 10) and Group Exercise + Potassium (SHR + E + K, exercise, potassium supplementation n = 10). Weekly, body weight (BW) and tail blood pressure (TAP) were measured. At the end of 16 weeks, a Oral Glucose Tolerance Test was performed. Albuminuria was determined in the baseline period, at 8th and at 16th week. After sacrifice, the analysis of glomerular sclerosis index and visceral fat weight was performed. Results: The TAP and BW did not change significantly. There was improvement in insulin sensitivity in SHR + E and SHR + K, but not in SHR + E + K. At week 16, albuminuria in all groups was significantly lower than the SHR control. The glomerular sclerosis index and visceral fat content were also significantly lower in all groups compared to control. Conclusion: An oral supplementation of potassium and exercise led to an improvement in glucose metabolism, in albuminuria and glomerular morphology, however, the overlap of the treatments did not show synergism. .

Protective effect of antihypertensive drug NO.1 on brain cortical tissue in spontaneously hypertensive rat / 中华老年医学杂志

Objective To investigate the protective effect of antihypertensive drug NO.1 on brain cortical tissue in spontaneously hypertensive rats.Methods A total of 60 spontaneously hypertensive rats (SHR,30 males and 30 females) and 12 healthy Wistar rats (6 males and 6 females) weighed (200 20) g,were randomly divided into 6 groups.Model group (SHR,n=12) and control group (healthy Wistar rats,n=12) were given the same dose of placebo.Captopril group (SHR,n=12) were given captopril 5 mg · kg-1 · d-1.The low-,median-and high-dose groups of antihypertensive drug NO.1 were given 0.25,0.5 and 1 g · kg 1 · d-1 respectively.After 4 weeks of treatment,carotid artery blood pressure was detected.All rats were sacrificed,and brain tissue samples were taken.The expressions of Bcl-2,Bax,necrosis factor NF-κB P65,chloride channel 2 and 3 (CLC-2 and CLC-3) were determined by RT-PCR and Western blotting.Results After 4 weeks of antihypertensive NO.1 treatment,SHR carotid artery blood pressure was (182.8 ± 7.3)mmHg in low dose group,(170.3±9.4) mmHg in medium dose group,and (163.9±10.6) mmHg in high dose group; and (205.4 ± 11.3)mmHg in the model group.Antihypertensive drug NO.1 significantly reduced blood pressure in spontaneously hypertensive rats,and had a concentrationresponse relationship (P＜0.05).Antihypertensive drug NO.1 decreased the expressions of Bax,CLC-2 and CLC-3,and increased the expressions of Bcl-2 and NF-κB P65.Conclusions Antihypertensive drug NO.1 plays a protective role in hypertension-induced cell injury by changing the metabolic enhancement in hypertension-induced cell volume decrease.

Aerobic exercise affects c-Src mRNA expression and c-Src activity in aortic vascular endothelial cells of spontaneous hypertensive rat models / 中国组织工程研究

BACKGROUND:Proto-oncogene c-Src plays an important role in regulating cardiovascular diseases such as hypertension. At present, there were no studies concerning exercise intervention effects on c-Src expression in aortic endothelial cels so as to regulate hypertension. OBJECTIVE: To observe the effects of aerobic exercise on c-Src mRNA expression and c-Src activity in the aorta blood vessel endothelial cels of spontaneous hypertensive rats. METHODS: A total of 8 male Wistar rats were considered as normal control group. Sixteen spontaneous hypertensive rats were randomly assigned to 8 rats as spontaneous hypertension group and 8 rats as spontaneous hypertension exercise group. Rats in the spontaneous hypertension exercise group carried on 90 minutes unloaded aerobic swimming every day, 6 days a week, for 8 weeks. The rats in the normal control group and spontaneous hypertension group did not swim. Blood pressure of rats was measured once a week. 8 weeks later, the c-Src mRNA expression and c-Src activity were determined in aortic vascular endothelial cels of rats in each group. RESULTS AND CONCLUSION: Compared with spontaneous hypertension group, blood pressure was lower, but c-Src mRNA expression and c-Src activity were significantly higher in the spontaneous hypertension exercise group. The c-Src activity and c-Src mRNA expression were higher in the spontaneous hypertension exercise group than normal control group and spontaneous hypertension group (P < 0.01). Results indicated that aerobic exercise can promote the increase in c-Src activity and c-Src mRNA expression in aortic endothelial cels of spontaneous hypertensive rats.

Combined use of telmisartan and pyridoxamine improved aortic remodeling in spontaneously hyperten-sive rats / 心血管康复医学杂志

Objective:To explore influence of monotherapy or combined use of telmisartan and pyridoxamine on aor-tic remodeling in spontaneously hypertensive rats (SHR)and its possible mechanism.Methods:A total of 48 male SHE were randomly and equally divided into hypertension control group,telmisartan group,group,and telmisartan+ group (combined treatment group). Kyoto Wistar rats of the same age and gender were regarded as normal blood pressure control group (normal control group). Thoracic aortic section were examined by related staining af-ter 16 weeks intervention to calculate the ratio of aortic wall thickness to radius of lumen (Tw/Rl),the ratio of wall area to lumen area (W/L),and the area ratio of media elastic fiber/collagen fiber. Concentrations of related en-zymes and receptor etc. of abdominal aortic were measured.Results:Compared with hypertension control group, there was significant rise in ratio of media elastic fiber/collagen fiber area and significant reduction in media collagen fiber/media area ratio in telmisartan group,pyridoxamine monotherapy group and combined treatment group,and there were significant decrease in Tw/Rl [(0.17±0.02)vs. (0.12±0.01)]and W/L [(0.29±0.03)vs. (0.22± 0.02)]ratios in combined treatment group,P <0.05 or <0.01;immunohistochemistry indicated that there were significant reductions in thoracic aortic receptor of advanced glycation end products (RAGE) [(0.24±0.03)vs.(0.17±0.03)]and extracellular signal-regulated kinase 1/2 (p-ERK1/2 )expression [(0.63 ± 0.06)vs. (0.37± 0.04)]in combined treatment group,P <0.05,<0.01. Fluorescence quantitative PCR indicated that medication can significantly reduce nicotinamide adenine dinucleotide phosphate (NADPH)oxidase subunit p47phox mRNA ex-pression (P <0.01 all),especially in combined treatment group (P =0.001).Conclusion:Combined use of telmis-artan and pyridoxamine is superior to the single use of either drug on improving thoracic aortic remodeling in SHR, the mechanism may be related to it reduces local expression of RAGE and p-ERK1/2 ,and inhibits oxidase subunit p47 of NADPH.

Effects of exercise training on cognitive function,ChAT and AchE activity in SHR/SP rat vascular dementia model / 重庆医学

Objective To investigate the effects of the exercise training on the cognitive function ,choline acetyltransferase (ChAT) activity and acetylcholinesterase (AchE) activity in stroke prone spontaneously hypertensive rat (SHR/SP) vascular de-mentia model .Methods 30 male SHR/SP rats were randomly divided into sham operation group ,model group and exercise group (n=10) .The VD model was established by the fractional ligation of bilateral carotid artery (2-VO) .The sham operation group and the model group were given the normal feeding without intervention after operation ;the exercise group adopted the treadmill exer-cise(DSPT-1) for 8 weeks .After the exercise ,the Morris maze test was conducted for evaluating the cognitive function in each group .The rats were finally killed for detecting the ChAT activity and AchE activity of hippocampus .Results In the positioning navigation training ,the latency period of the sham operation group was significantly short than that of the exercise group and the model group ,but the latency period of the exercise group was obviously short than that of rats in the model group (P<0 .05);in the spatial exploration test ,the rats in the sham operation group had more frequency of crossing platform than the other two groups ,the exercise group had more frequency of crossing platform in platform quadrant than the model group (P<0 .05);the exercise training could increase the ChAT activity and lower the AchE activity of hippocampus .Conclusion The exercise training can improve the function of hippocampal cholinergic system in SHR/SP and then increase the cognitive ability .

Bone healing of mandibular critical-size defects in spontaneously hypertensive rats

Few articles have shown changes in bone metabolism caused by hypertension. The objective of this study was to investigate the relationship between hypertension and bone healing. Circular critical-size defects 5 mm and 2 mm in diameter were created, respectively, on the left and right side of the mandible in 40 spontaneously hypertensive and 40 control Wistar-Kyoto rats. Five animals from each strain were killed 2, 3, 5, 10, 15, 30, 60 and 90 days after surgery. The macroscopic evaluation showed great mandibular angle deformation on the left side and non-healed defects on both sides and groups. Histological evaluation revealed similar bone healing on both sides, with initial necrosis in the central area, and fibrosis and angiogenesis within the first 5 days. From the 10th postoperative day on, the newly formed bone displayed progressive thickening until the 90th postoperative day, when the defect margins presented a compact bone structure. Furthermore, the statistical analysis of the histometric data did not reveal any significant hypertension effect on bone healing in the defect area. These results suggest that bone healing was not different between spontaneously hypertensive rats and control rats.

Influence of arterial hypertension on colonic healing in rats / Influência da hipertensão arterial na cicatrização colônica em ratos

PURPOSE: Evaluation of colonic healing in spontaneously hypertensive rats. METHODS: Fifty male, young and inbred rats were used. Twenty-five Wistar Kyoto rats (WKY) as control and twenty-five spontaneously hypertensive rats (SHR) as an experimental group. Colotomy and bowel suture at 2.5 cm from the peritoneal reflection were performed. All animals were allocated randomly into sub-groups for review at the third, seventh and fourteenth days after surgery. We evaluated the concentration of angiotensin II, the burst pressure, epithelialization, the organization of the tunics of the bowel wall, inflammatory response and collagen deposition. RESULTS: The burst pressure, epithelialization, organization of the tunics and collagen deposition was not significant between groups. The inflammatory reaction was more intense in the control group on the third postoperative day (p=0.023) as the experimental group on the remaining time. CONCLUSION: Systemic arterial hypertension in rats did not influence significantly the healing process of colonic anastomoses.

OBJETIVO: Avaliar a cicatrização colônica em ratos espontaneamente hipertensos. MÉTODOS: Cinquenta ratos machos, jovens e isogênicos. Vinte e cinco ratos da linhagem Wistar Kyoto (WKY) como controle e vinte e cinco ratos espontaneamente hipertensos (SHR) como grupo experimento. Realizou-se colotomia e colorrafia a 2,5 cm da reflexão peritoneal. Alocaram-se os animais aleatoriamente em sub-grupos para avaliação no terceiro, sétimo e décimo quarto dias de pós-operatório. Foram avaliados a concentração de angiotensina II, a resistência da anastomose à insuflação, a epitelização, a organização das túnicas da parede intestinal, a reação inflamatória e a deposição de colágeno. RESULTADOS: A avaliação da resistência da anastomose, epitelização, organização das túnicas e deposição de colágeno não foi significativa entre os grupos. A reação inflamatória foi mais intensa no grupo controle na avaliação do terceiro dia de pós-operatório (p=0,023) igualando-se ao grupo experimento nos demais tempos. CONCLUSÃO: A hipertensão arterial sistêmica, em ratos, não influenciou de forma significante no processo cicatricial de anastomoses do cólon.

Influence of exercise training and angiotensin-converting enzyme inhibitor on blood pressure, aortic compliance and cardiovascular tissue in spontaneously hypertensive rats / 心血管康复医学杂志

Objective: To explore influence of exercise training and angiotensin-converting enzyme inhibitor (perindopril) on blood pressure, aortic compliance and cardiovascular tissue structure in spontaneously hypertensive rats (SHR). Methods: A total of 38 SHR aged seven weeks were divided into control group (C group, n=9), exercise group (Exe group, n=9), perindopril group (Per group, n=10) and perindopril + exercise group (Per＋Exe group, n=10). SHRs were observed for eight weeks, and tail-cuff method was used to measure systolic blood pressure（SBP）once a week. When rats were 15 weeks old, regression line（once linear function）was obtained by single regression analyzing the relation between blood pressure and pulse wave velocity（PWV）. The b of this once linear function was used as index of aortic compliance（there was negative relationship between b and aortic compliance）. The left ventricular mass （LVM）/body weight（BW）was used to evaluate ventricular thickening, and aortic weight （AO）/ BW was regard as index of vascular thickening. Results: Compared with C group, SBP of Exe group significantly decreased on 12 weeks old (P0.05）. On 15 weeks old, the LVM/BW [(2.19±0.36) mg/g, (2.16±0.32) mg/g ] and AO/BW [(0.20±0.01) mg/g, (0.19±0.01) mg/g] of Per group and Per+ Exe group significantly decreased compared with C group [(2.95±0.58) mg/g, (0.26±0.01) mg/g], P<0.05 all, but there was no significant difference in these indexes between Per group and Per+ Exe group and between C group and Exe group（P＞0.05 both）. The b （index of aortic compliance）were [（C group ：（21.2±1.2）, Exe group：（20.5±1.4）, Per group：（14.8±1.6），Per＋Exe group：（15.0±1.3）] respectively, there was no significant difference between Per group and Per+ Exe group and between C group and Exe group（P＞0.05 both）. Conclusion: The exercise training of eight weeks possesses certain lowering blood pressure tendency, but no significant influence yet for aortic compliance and cardiovascular tissue structure in spontaneously hypertensive rats.

Estudo do efeito do TERPY [Ru(terpy)(bdq)NO+]3+, um novo doador de óxido nítrico, na reatividade vascular e na pressão arterial de ratos espontaneamente hipertensos (SHR) / Study of the effect of TERPY [Ru (terpy) (bdq) NO +] 3 +, a new nitric oxide donor, vascular reactivity and blood pressure in spontaneously hypertensive rats (SHR)

O uso clínico de drogas que liberam óxido nítrico (NO) é limitado por seus efeitos colaterais. A hipotensão induzida pelo doador clássico de NO, nitroprussiato de sódio (NPS) é rápida, transiente e induz à taquicardia reflexa, o que pode ser um efeito indesejável em pacientes com doença cardíaca e uma limitação para a terapia anti-hipertensiva. Este estudo avaliou o efeito hipotensor e vasodilatador do novo doador de NO [Ru(terpy)(bdq)NO+]3+ (TERPY) e comparou com os resultados obtidos com o NPS em ratos Wistar e ratos espontaneamente hipertensos (SHR). Em outra parte do estudo, foram estudadas diferenças no mecanismo de ação desta droga entre aortas de SHR jovens e velhos. Diferente do observado para o NPS, a hipotensão induzida pelo TERPY é lenta, duradoura e não leva a alterações da frequência cardíaca. Além disso, o TERPY libera quantidades semelhantes de NO em aortas de SHR e Wistar, induzindo relaxamento parcialmente dependente de GCs em ambos os grupos, ao contrário do NPS, que libera mais NO em aortas de SHR e também é mais potente e eficaz em aortas desses animais. Fatores como o estresse oxidativo e a atividade da PDE5 são importantes para o relaxamento do TERPY em SHR, mas a inibição da PDE5 não aumenta a potência do TERPY em aortas de ratos Wistar. Além disso, o relaxamento induzido pelo TERPY é mais potente em anéis de aorta de SHR velhos do que novos. Os mecanismos de ação do TERPY são semelhantes nas aortas desses animais, mas, interessantemente, a incubação com Apocinina aumenta a potência do TERPY em aortas de SHR jovens, mas não de velhos. Em conjunto, estes dados demonstram que o composto TERPY é um doador de NO que possui vantagens em relação ao NPS. Além disso, é mais potente em aortas de animais hipertensos velhos, o que é mais uma vantagem para sua utilização e um incentivo para a realização de novos estudos que possam contribuir para entender melhor seu mecanismo de ação

The clinical use of nitric oxide (NO) releasing drugs is limited by their harmful effects. The hypotension induced by the classic NO donor, sodium nitroprusside (SNP) is fast, transient and induces reflex tachycardia, which can be an undesirable effect in patients with heart disease and a limitation for the anti-hypertensive therapy. This study evaluated the hypotensive and vasodilatory effects of the new NO donor [Ru(terpy)(bdq)NO+]3+ (TERPY) in Wistar rats and spontaneously hypertensive rats (SHR). In another part of the study, we investigated the differences in the mechanism of action of this drug between aortas of young and old SHR. Different from what is observed for SNP, the hypotension induced by TERPY is slow, long lasting and doesn’t lead to alterations in the heart rate. Besides, TERPY releases similar amounts of NO in SHR and Wistar aortas, inducing a relaxation partially dependent on GCs in both groups, contrary to SNP, which releases more NO in aortas of SHR and is also more potent and efficient in the aortas of these animals. Factors as oxidative stress and the activity of PDE5 are important to the relaxation of TERPY in SHR, but the inhibition of PDE5 doesn’t increase the potency of TERPY in aortas of Wistar rats. Furthermore, the relaxation induced by TERPY is more potent in aortas of old SHR than of young ones. The mechanisms of action of TERPY are similar in the aortas of both groups, but, interestingly, the incubation with Apocynin increases the potency of TERPY in aortas of young SHR, but not of old ones. Taken together, these data show that the compound TERPY is a NO donor that has advantages in relation to SNP. Moreover, it’s more potent in aortas of old hypertensive animals, which is another advantage for its use and an incentive for the elaboration of new studies that could contribute to understand its mechanism of action

Can Wistar rats be used as the normotensive controls for nerve morphometry investigations in spontaneously hypertensive rats (SHR)? / Ratos Wistar podem ser utilizados como os controles normotensos dos ratos espontaneamente hipertensos (SHR) em investigações morfométricas de nervos periféricos?

PURPOSE: We compared the sural nerve morphology among Wistar (WR), Wistar-Kyoto (WKY) and Spontaneously hypertensive (SHR) rats, including the nerve fascicles and myelinated fibers morphometry. METHODS: Age matched (20 weeks) female WR (N=6), WKY (N=6) and SHR (N=7) had their right and left sural nerves removed, embedded in epoxy resin, and observed by light microscopy. Morphometric analysis was performed with the aid of computer software. RESULTS: Despite presenting the same age, WR were heavier than WKY and SHR, as were SHR compared to WKY. Systolic arterial pressure was higher in SHR compared to WR, but no differences between SHR and WKY or WR and WKY were observed. The sural nerves were morphometrically symmetric between proximal and distal segments on the same side and between sides in all strains with no differences in the myelinated fiber number. Schwann cell number and density were smaller in SHR and G ratio was larger in SHR, indicating that SHR have thinner myelinated fibers. CONCLUSION: Sural nerve morphology is similar between WKY and WR, allowing the use of WR as the SHR controls in morphological investigations involving peripheral neuropathies.

OBJETIVO: Comparar a morfologia do nervo sural em ratos Wistar (WR), Wistar Kyoto (WKY) e espontanemanete hipertensos (SHR), incluindo a morfometria dos fascículos e fibras mielínicas. MÉTODOS: Os nervos surais direito e esquerdo de WR (N=6), WKY (N=6) e SHR (N=7), com 20 semanas de idade foram removidos e preparados para inclusão em resina epóxi e microscopia de luz. A morfometria foi realizada com o auxílio de um programa de computador. RESULTADOS: Apesar de apresentarem a mesma idade, WR são mais pesados que os WKY e SHR. Ainda, SHR são mais pesados que os WKY. A pressão arterial sistólica foi significativamente maior nos SHR comparados aos WR, sem diferença entre WKY e SHR ou WR e WKY. Os nervos surais são morfometricamente simétricos entre segmentos proximal e distal e entre lados direto e esquerdo nas três diferentes linhagens, sem diferença no número de fibras mielínicas. O número e a densidade de células de Schwann foram menores e a razão G foi maior nos SHR, indicando a presença de fibras mielínicas com bainha mais fina. CONCLUSÃO: A morfologia do nervo sural é semelhante ente WR e WKY, permitindo o uso de WR como controles dos SHR nas investigações envolvendo neuropatias periféricas.