The Effects Of Angelica On Myocardial Apoptosis And The Ventricular Remodeling After Myocardial Infarction

Objective: To investigate the effects of Angelica on ventricular function , myocardial apoptosis and expression of apoptosis-associated genes in the infarct border zone in rats with myocardial infarction (MI), as well as possible mechanisms of Angelica's inhibitory effects.Methods: Male Wistar rats were divided into three groups: sham, MI and MI + Angelica. MI was induced by ligating the left anterior descending coronary artery. After 24 hours of ligation, the MI + Angelica group was treated with Angelica (2ml.100g^-1.d^-1, i.p.) while the sham and MI groups were treated with placebo (saline, i.p.). Left ventricular function was measured at week 1, week 2, week 3 and week 4 after operation. Myocardial apoptosis and protein expression of Bax and Bcl-2 genes were detected by TUNEL staining and immunohistochemistry.Results: 1) After MI, left ventricular function deteriorated; compared with MI, left ventricular function in the MI + Angelica group was significantly improved in the late phase (P < 0.01). 2) Infarct size was not significantly different in MI vs MI + Angelica; after week 4 of MI, relative heart weight and left ventricular weight were markedly increased (P < 0.01). Angelica inhibited heart and left ventricular hypertrophy compared with week 4 of MI (P < 0.05). 3) There were apoptotic myocytes in the infarct border zone in the MI and MI + Angelica groups; however, the number of apoptotic myocytes was decreased significantly in the MI + Angelica group compared with MI (P < 0.01). 4) Positive expression of Bax and Bcl-2 genes was markedly increased in the MI and MI + Angelica groups compared with sham. Angelica significantly inhibited expression of the Bax gene (P < 0.01) and significantly increased Bcl-2 gene expression (P < 0.01) compared with MI.Conclusions: Myocyte apoptosis and expression of Bax and Bcl-2 genes are significantly increased in rat hearts with MI, whereas ventricular function is decreasedafter MI. Angelica injection has a beneficial effect on treatment of MI because of its downregulation of Bax gene expression and its upregulation of Bcl-2 gene expression.