L-精氨酸对肾性高血压大鼠主动脉功能的保护作用

目的:探讨L-精氨酸(L-Arg)对二肾一夹(2K1C)肾性高血压大鼠主动脉内皮功能的影响.方法:雄性SD大鼠术后4 w,测量平均动脉压(MAP)、主动脉壁环鸟苷酸(cGMP)含量,并取其主动脉进行离体血管环实验.结果:2K1C大鼠MAP升高,主动脉对乙酰胆碱的舒张反应明显减弱,而对乙酰胆碱的收缩反应显著增强,cGMP含量显著减少.口服L-Arg 4 w不能降低2K1C大鼠的MAP,主动脉对乙酰胆碱的收缩、舒张反应部分恢复,cGMP含量明显升高.各组大鼠的主动脉环用NOS抑制剂L-硝基-精氯酸甲酯(L-NAME)孵育后,对硝普钠的最大舒张反应无显著不同.结论:L-Arg可能通过增加一氧化氮(NO)的生成,改善2K1C肾性高血压大鼠的主动脉内皮功能.

Protective role of L-arginine on aortic function in rats with renal hypertension

Objective: To explore the protective role of L-arginine on the function of aortic endothelium function in rats with renal hypertension.Methods:Left renal artery of male Spragrue-Dawley rats was partially occluded for 4 weeks,mean arterial pressure and cGMP content of the aorta were measured,isometric tension changes of aortic rings were recorded.Results:The mean arterial pressure of 2K1C rats was significantly elevated.In isolated aortic rings,acetylcholine-induced relaxation was suppressed,acetylcholine-induced contraction was enhanced,the level of aortic cGMP content was significantly lowered.MAP in 2K1C rats could not be lowered after 4 weeks oral administration of L-arginine,the acetylcholine induced relaxation and contraction responses partiaiiy restored,increased aortic cGMP content markedly.In contrast,sodium nitroprusside induced maximal relaxation in presence of NG-nitro-L-arginine methyl ester(L-NAMEd)id not differ significantly among the three groups.Conclusion:L-Arginine may improve aortic endothelial function of 2K1C renal hypertensive rats through increasing production of NO and decreasing release of contracting factor.