Effect of Erxiantang on Cardiac Function and Blood Pressure Dynamic Evolution in Ovariectomized Rats / 中国实验方剂学杂志

ABSTRACT

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.