Protective effects of breviscapine on myocardial hypertrophy and fibrosis induced by isoproterenol in rats

Aim To investigate the protective effects of breviscapine(Bre) on myocardial hypertrophy and fibrosis induced by isoproterenol (Iso) in rats and its mechanism. Methods Myocardial hypertrophy and fibrosis model of rats were induced by injection of Iso for 7 days(5 mg·kg -1·d -1,sc).From day 2～15,rats were treated with Bre 12.5 and 25 mg·kg -1·d -1 ip,the NS control and Iso model group received saline injection.On day 15,animals were killed by decapitation,monitored in terms of myocardial indexes (heart weight/boday weight, HW/BW and left ventricalar weight/body weight,LVW/BW);the contents of angio- tensin Ⅱ(AngⅡ),nitric oxide(NO) and hydroxyproline and the activity of Na+,K+-ATPase and Ca 2+-ATPase in left ventricle were assayed with radioimmunoassay and spectrophotometry,respectively. Results Compared with the NS control group, the myocardial indexes, the level of AngⅡ and hydroxyproline in left ventricle were markedly increased and NO content, activity of Na+,K+-ATPase and Ca 2+-ATPase in left ventricle were decreased in Iso model group;treatment with Bre 25 mg·kg -1·d -1 significantly reduced the myocardial index and content of AngⅡ and hydroxyproline in left ventricle,increased the NO content ,enhanced the activity of Na+,K+-ATPase and Ca 2+-ATPase.Conclusion Bre can alleviate myocardial hypertrophy and fibrosis induced by Iso in rats.