Dynamic Evolution of Cardiac Function and Glucose and Lipid Metabolism in Ovariectomized Rats and the Intervention Effect of Erxian Decoction

Abstract

Aims. Abnormal changes in cardiac function have been reported in menopausal women, but there are few clinical studies on this topic. Erxian decoction (EXD) is a classic prescription that is widely used in the treatment of female menopausal diseases. The purpose of this study was to investigate the dynamic evolution of cardiac function and glucose and lipid metabolism in ovariectomized (OVX) rats and the intervention effect of EXD. Materials and Methods. The OVX climacteric rat model was established by bilateral ovariectomy. After successful modeling, the rats were randomly divided into four groups: the sham operation (SHAM) group (equal volumes of purified water), OVX group (equal volumes of purified water), estradiol (E2) group (1.8 × 10−4 g/kg), and EXD group (9 g/kg). Each group of rats was treated for 16 weeks. At the 4th, 8th, 12th, and 16th weeks after treatment, the cardiac function of the rats in each group was evaluated by ultrasound. The coaxial method was used to measure blood pressure (BP). Serum endothelin-1 (ET-1) and angiotensin-2 (Ang II) levels were determined by the enzyme-linked immunosorbent assay (ELISA). The strip method was used to measure fasting blood glucose (FBG). The serum total cholesterol (TC) and triglyceride (TG) levels of rats were measured with the oxidase method. Direct methods were used to measure serum high-density lipoprotein (HDL-C) and low-density lipoprotein (LDL-C) levels. At week 16 of dosing, serum E2 levels were determined by E2 radioimmunoassay. The myocardium and uterus of the rats in each group were stained with HE (hematoxylin-eosin). The ultrastructure of the rat myocardium was observed by electron microscopy. Results. After the 16th week of treatment, the serum E2 level decreased ( $P<0.05$ ), and the uterus was atrophied in OVX rats. The cardiac ejection fraction (EF%) decreased at 4 weeks after treatment, and systolic and diastolic function decreased after 12 weeks. After the 16th week, the EF%, which reflects the “pump” function of the heart, decreased significantly ( $P<0.05$ or $P<0.01$ ). At the 4th, 8th, 12th, and 16th weeks of treatment, the systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean pressure (MBP) of the rats in the OVX group increased with time ( $P<0.05$ or $P<0.01$ ). The serum ET-1 and Ang II levels of rats in the OVX group increased ( $P<0.05$ or $P<0.01$ ). In the OVX group, FBG was increased ( $P<0.05$ or $P<0.01$ ), and blood lipids, especially LDL-C, were significantly increased ( $P<0.05$ or $P<0.01$ ). After the 16th week of treatment, the myocardial tissue of OVX rats showed obvious pathological changes. EXD significantly increased serum E2 levels ( $P<0.01$ ), decreased ET-1 and Ang II levels ( $P<0.01$ ), reduced the cardiac function risk factors BP, FBG, and blood lipids, and significantly improved cardiac function and structural changes in OVX rats ( $P<0.05$ or $P<0.01$ ). Conclusions. EXD can improve abnormal cardiac structure and function in OVX rats.