Abstract: Objective To observe the protective effect of spironolactone on heart of hypertensive SD rats.Methods 30 male SD rats were randomly divided into the control group,hypertensive group(HS group),low spironolactone dose group(HSL group)and high spironolactone dose group(HSH group).The animals except the control group were treated with L-NAME 50 mg/kg/d.Then the animals of the HS group were fed with 1% sodium chloride water solution.Those of the HSL and HSH groups were treated same but the former added with spironolactone 20 mg/kg/d,the later added with spironolactone 100 mg/kg/d.8 weeks late,the animals were killed and hearts were taken out to observe following items:myocardial cross-sectional area,ratio of per-arteriolar fibrous area/arteriolar luminal area of arterioles,ratio of collagen area/total myocardial area,myocardial necrosis and inflammation.Results The myocardial cross-sectional areas in the HS group were significantly more than those in other 3 groups(P<0.01).Collagen ratios of the HS group were significantly higher than others(P<0.01).The ratios of arteriolar wall area versus luminal area in the HS group were significantly higher than those of control and HSH groups(P<0.01).Myocardial injuries in the HS group were more severe than those of other 3 groups.There were no differences between HSL and HSH groups.Conclusion Spironolactone has protective effect on heart of hypertensive SD rats.

Key words: spironolactone, hypertension, cardio protection