The study of protective effects of low molecular weight heparin on isoproterenol-induced cardiac hypertrophy and fibrosis in rats

Objective To study the effect of low molecular weight heparin (LMWH) on cardiac hypertrophy and fibrosis induced by isoproterenol (ISO) in rats and its mechanism. Methods Cardiac hypertrophy and fibrosis in rats were induced by subcutaneous administration of ISO. LMWH (200 U·kg·1*d-1) was administered by subcutaneous injection to treat the rats. The morphological changes and heart mass index,the content of nitric oxide (NO) in serum,the activity of calcineurin (CaN) ,the content of collagen in the heart were determined after 10 days of treatment. Results The results showed that significant cardiac hypertrophy and fibrosis in rats were induced by ISO on the 10th day. Heart mass index,the activity of CaN and the content of collagen in the heart were increased (P 0.01) ,the content of NO in serum was decreased (P 0.01) ,but all these changes were reversed in LMWH group,with decreased weight of heart and activity of CaN and less content of collagen in the heart (P 0.01) and increased content of NO in serum (P 0.01). Conclusions LMWH can alleviate the cardiac hypertrophy and fibrosis induced by ISO in rats.