Résumé
Objective::To investigate the evolution of cardiac function and blood pressure in ovariectomized rats and the effect and mechanism of Erxiantang. Method::Healthy 10-week-old female SPF SD rats were randomly divided into sham operation group, model group, estrogen group(estradiol valerate, 0.18 mg·kg-1) and Erxiantang group(7.5 g·kg-1). The rats were intragastrically administered 2 weeks after ovariectomy, once a day for 12 weeks.Sham operation groups and model groups were given equal volumes of purified water.At the 4th week, 8th week, and 12th week after administration, the cardiac function, blood pressure, and levels of estrogen (E2) in rat serum were measured by non-invasive ultrasound cardiogram (UCG), tail artery detection techniques and radioimmunoassay.The levels of endothelin-1 (ET-1) and angiotensin 2(Ang Ⅱ) in rat serum were detected by enzyme-linked immuno sorbent assay (ELISA). The cardiac morphology and apoptosis were detected by hematoxylin-eosin (HE) staining, electron microscopy and Terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL). Result::Compared with sham operation group, the ejection fraction (EF) decreased and the left ventricular end systolic volume (LVVols) increased in the model group at 4th week after administration(P<0.05). There was no significant difference in cardiac function between the groups at 8th week.The left ventricular end diastolic diameter (LVIDs), LVVols, left ventricular end diastolic diameter (LVIDd), and left ventricular end diastolic volume (LVVold) were significantly increased in the model group at 12th week (P<0.01). At the 4th weeks, 8th week and 12th week, the systolic blood pressure (SBP) of the model group increased (P<0.05) and showed an increasing trend, and the diastolic blood pressure (DBP) did not change significantly.At the 12th week, the levels of E2 in serum decreased (P<0.05), ET-1 and Ang Ⅱ increased of the model group (P<0.01). The cardiac myofibrils were irregular, some myofilament was broken, and mitochondrial palsy was disordered, broken or disappeared, and cardiac apoptosis increased (P<0.01). Compared with the model group, myocardial contraction and diastolic function were significantly improved in Erxian decoction group, and blood pressure was decreased.The levels of E2 in serum was increased (P<0.05). The levels of ET-1 was decreased (P<0.05), and AngⅡ in serum was significantly decreased (P<0.01). The mitochondrial morphological structure was improved and the cardiac apoptotic rate was significantly decreased (P<0.01). Conclusion::After the ovariectomy, the rats showed a series of pathological changes such as decreased heart function and increased blood pressure.Compared with the decrease of heart function, the changes of blood pressure appeared earlier.Erxiantang exerts its intervention on cardiac function and blood pressure in ovariectomized rats by regulating E2, blood active substances and cardiac apoptosis.
Résumé
Objective To investigate the effects of erythropoietin (EPO) on myocardial apoptosis and protein kinase B (AKT) expression in rats of chronic heart failure (CHF). Methods Thirty male adult SD rats were randomly divided into two groups, sham-operated (Sham) group (n=6) and model (Model) group (n=24). The abdominal aortic coarctation was used to build CHF model. Sixteen survived rats after operation were randomly divided into two groups including EPO group and con-trol (Control) group. EPO group was received 3 000 U/kg EPO intraperitoneal injection 3 times/week for 4 weeks, and Sham group and Control group were received same volume of normal saline. The echocardiography was used to evaluate cardiac function after 4 weeks, 8 weeks and 12 weeks of treatment. After 12 weeks, all rats were sacrificed after 24 h fasting. The cell morphology and myocardial apoptosis were observed, and apoptosis index (AI) was calculated. Myocardial P-AKT/AKT pro-tein expression was detected by Western blot assay. Results Echocardiography showed that ventricular hypertrophy was found in model group after four weeks, heart failure 8 weeks. Compared with Control group, left ventricular ejection fraction (LVEF) was significantly higher after EPO intervention for 4 weeks (P < 0.05), systolic interventricular septum thickness (IVSs), end-systolic left ventricular posterior wall thickness (LVPWs), diastolic interventricular septum thickness (IVSd), af-ter left ventricular end-diastolic wall thickness (LVPWd) were significantly lower (P<0.05). The value of AI was significant-ly lower in EPO group than that of Control group (23.87%±1.45%vs 35.58%±2.81%, P<0.01). The OD value of P-AKT/AKT was significantly decreased in Control group (0.35±0.06) than that of Sham group (0.81±0.17), the value was significant-ly increased in EPO group (1.61±0.16) than that of Control group (P<0.01). Conclusion EPO can improve heart function, inhibit myocardial apoptosis,and promote pro-phosphorylation of AKT in rats with chronic heart failure.
Résumé
Objective To investigate calcineurin signaling pathway which mediates myocardium apoptosis of right heart in rats with chronic hypoxia and the potential mechanisms of it.Methods A rat model of right ventricular hypertrophy(RVH) was established induced by chronic hypoxia(95-105 mL?L-1 O2).Used randomized block design based on different brood,30 rats were divided into 3 groups:treatment group with cyclosporine A(CsA,10 mg?kg-1?d-1,intraperitoneal injection),chronic hypoxia group,normal control group(with normal oxygen).The rats in CsA treatment group and chronic hypoxia group were exposed to normobaric chronic hypoxia(95-105 mL?L-1 O2,21 days).Apoptotic index(AI),calcineurin A?(CnA?) mRNA levels,Bcl-2 mRNA levels and the protein expression levels of CnA?,nuclear factor 3 of activated T cells(NFAT3) and Bcl-2 in right ventricle were investigated.Results 1.The AI of treatment group with CsA was higher than that in chronic hypoxia group(P