Abstract:
OBJECTIVE To investigate the protective effect and potential mechanism of Tibetan medicine Ershiwei Chenxiang Wan(ECW) on myocardial fibrosis in rats with hypoxic pulmonary hypertension(HPH).
METHODS Sixty male SD rats were randomly divided into 5 groups: the control group, HPH group, HPH+0.6 g·kg−1 ECW group, HPH+1.2 g·kg−1 ECW group, and HPH+TMZ group. Except for the control group, rats in the other groups were subcutaneously injected with semaxinib(SU5416), and then placed in a hypobaric oxygen chamber for 3 weeks, with the chamber opened for 1 h daily for intragastric administration. The body weight of rats was recorded every day. At the end of the experiment, pulmonary artery pressure(PAP) and right ventricular pressure(RVP) were measured; blood cell count was performed; serum levels of N-terminal pro-brain natriuretic peptide(NT-proBNP), creatine kinase isoenzyme MB(CK-MB) and lactate dehydrogenase(LDH) were detected by serum biochemical assays; the right ventricular hypertrophy index and cardiac index of rats were calculated; HE staining and Masson staining were used to observe the pathological changes and fibrosis degree of cardiac tissues; Western blotting was applied to determine the protein expressions of Collagen Ⅰ, osteopontin(OPN), Akt, phosphorylated Akt(pAkt), glycogen synthase kinase-3β(GSK-3β), phosphorylated GSK-3β(pGSK-3β) and β-catenin in myocardial tissues.
RESULTS Compared with the control group, rats in the HPH group showed slow body weight gain, increased red blood cell count, elevated PAP and RVP, higher serum levels of NT-proBNP, CK-MB and LDH, increased cardiac index and Fulton index, obvious myocardial fibrosis, up-regulated expression of Collagen Ⅰ, as well as increased expressions of OPN, pAkt, pGSK-3β and β-catenin. After intervention with ECW, all the above abnormal indicators were improved to varying degrees, with more remarkable effects observed in the 1.2 g·kg−1 ECW group.
CONCLUSION Tibetan medicine ECW can effectively alleviate myocardial injury in HPH rats, and its mechanism may be related to inhibiting the activation of OPN/Akt/GSK-3β signaling pathway, down-regulating the expression of pathway-related proteins, thereby reducing the process of myocardial fibrosis.