Abstract:

To investigate the expression of p53  in myocardium tissue of ispproterenol (Iso)[KG-*3]-induced myocardial fibrosis  rats and its signigicance and clarify the effect in inyocardial of fibrosis. Methods 25 male Wistar rats were randomly divided  into five groups: control group，model groups(12 h,24 h,1 week and 3 weeks)(n=5). Except control group,all the rats in the other groups were treated with Iso to bulit rat myocardial injury models(15 mg·kg^-1).The expressions of P53 protein and p53 mRNA were detected with immunohistochemical staining and RT-PCR.Results The immunohistochemical results showed that the P53 protein expressions were  increased 12 and 24 h after Iso injection  compared with  control group（P<0.05）and the  protein expressions were obviously increased  1 week and 3 weeks after Iso injection（P<0.01）.The RT-PCR results showed that the p53 mRNA was obviously increased  at 12 h (P<0.05),arrived a peak at 24 h (P<0.01)　and was gradually decreased at 1 week,but still higher than normal level (P<0.05). Conclusion The P53 protein   expression is increased in rat myocardium tissue and the expression of p53 gene is up-regulated,suggesting that p53 has an important role in rat myocardial fibrosis.

Key words: p53 gene;isoproterenol;myocardial fibrosis;apoptosis