目的研究Ｌ－精氨酸（Ｌ－Ａｒｇ）对异丙肾上腺素（ＩＳＰ）致害心肌的影响。方法大鼠分四组；①ＩＳＰ组ＩＳＰ４０ｍｇ／ｋｇ／ｄａｙ×２，皮下注射；②对照组体重匹配的大鼠注射同容量的生理盐水；③Ｌ－Ａｒｇ组腹腔注射Ｌ－Ａｒｇ１５ｇ／ｋｇ／ｄａｙ×２；④ＩＳＰ＋Ｌ－Ａｒｇ组。结果ＩＳＰ处理的大鼠心重／体重比值、心肌内ＮＯ、钙的水平以及血清ＬＤＨ水平高于对照组（Ｐ＜００１），而心肌中ＧＳＨ－ＰＸ及Ｌ－Ａｒｇ水平低于对照组（Ｐ＜００１）结论Ｌ－Ａｒｇ可部分逆转ＩＳＰ致心肌肥厚，心肌中ＮＯ、钙、Ｌ－Ａｒｇ、ＧＳＨ－ＰＸ及血清ＬＤＨ水平的变化 Objective To investigate the effect of L-arginine on myocardial damage induced by isoproterenol (ISP). Methods The rats were divided into four groups: (1) ISP40mg / kg / day × 2, injected subcutaneously; ② The rats in the control group were injected with the same volume of normal saline; the L-Arg group were intraperitoneally injected with L-Arg15g / kg / day × 2; ④ISP + L-Arg group. Results Compared with the control group (P <001), the level of GSH-PX and L-Arg in myocardium of ISP-treated rats was significantly lower than that of the control group P <001)  Conclusions L-Arg can partially reverse the changes of myocardial hypertrophy, myocardial NO, Ca, L-Arg, GSH-PX and serum LDH