L-精氨酸对肾性高血压大鼠主动脉肥厚的影响

The Effects of L-arginine on Aortic Hypertrophy in Renovascular Hypertensive Rats

目的探讨一氧化氮前体L-精氨酸对肾血管性高血压大鼠主动脉肥厚的影响。方法采用两肾一夹Glodblatt肾血管性高血压大鼠模型。所有大鼠被随机分为4组(每组10只):假手术对照组,高血压对照组,L-精氨酸治疗组(于术后第5周开始每天给予L-精氨酸200mg/kg),L-NAME处理组(于术后第5周开始每天同时给予L-NAME 10mg/kg及L-精氨酸200mg/kg)。采用标准尾套法间接检测清醒大鼠血压。给药8周后,处死大鼠,分离胸主动脉用于检测主动脉重/体重比、胸主动脉中膜厚度及中膜截面积(应用石蜡切片的彩色图像分析技术)。结果L-精氨酸治疗明显抑制了肾动脉狭窄术后的血压升高,减小了主动脉重/体重比、主动脉中膜厚度及中膜截面积。L-NAME明显抑制了L-精氨酸的上述作用。结论长疗程L-精氨酸治疗在抗高血压的同时也具有抑制主动脉肥厚的作用。

Objective To investigate the role of L-arginine, a nitric oxide （NO） precursor, on aortic hypertrophy in renovascular hypertensive rats. Methods The Glodblatt renovascular hypertension model was induced in rats by twokidney one clip method. All the rats were randomly divided into four groups （n=10 per group）： ①the sham-operated control group; ②the 2K1C renohypertensive control group; ③the 2K1C＋L-Arg group, the two-kidney-one-clip rats were treated with L-arginine at a dose of 200mg· kg^-1·d^-1 from 5th week after renal artery constriction; ④the 2KIC＋L-NAME group, the two-kidney-one-clip rats were treated with LNAME （10 mg· kg^-1·d^-1） plus L-arginine （200mg · kg^-1·d^-1） from 5th week after renal artery constriction. Indirect blood pressure was measured in conscious rats by the standard tail-cuff methods. After treatment with both drugs for 8 weeks, the rats were killed and the thoracic aorta was removed to determine the aorta weight/body weight ratio, media thickness and media cross-sectional area of thoracic aorta by an color image analysis system. Results L- arginine significantly inhibited the increase of blood pressure, aorta weight/body weight ratio （AW/ BW）, media thickness and media cross-sectional area of thoracic aorta, and these effects of L-arginine could be inhibited by L-NAME. Conclusion Oral treatment with L-arginine inhibit aortic hypertrophy in renovascular hypertensive rats.