摘要
Under the catalysis of dioxygenase L-arginine is converted to L-citrulline and nitric oxide,the latter exhibits endothelium derived relaxing factor(EDRF)-like actions.N^G-nitro-L-arginine has an inhibitory effect on the biosynthesis of EDRF in vitro and in vivo,hence it is an EDRF antagonist.The results of the present work indicate that both N^G-NO_2-L-Arg-OH and HCl·N^G-NO_2-L- Arg-OCH_3 have vasodilating effect in vitro,but produced dose-depending increase in mean arterial blood pressure(MAP)in vivo.In vitro HCl·N_G-NO_2-L-Arg-N_G-NO_2-L-Arg-OCH_3 relaxed rat aortic strip pretreated with noradrenaline(NE).In vivo,however,it produced biphasic effect,i.e,decreased MAP at lower dose and increases MAP at higher dose, N_G-Tos-L-Arg-N_G-Tos-L-Arg-OH produced dose-depending vasodilating and hypotensive actions.
在二氧化酶作用下,L-精氨酸转变为 L-胍氨酸和 NO,此 NO 显示 EDRF 样的重要的生物活性。N^G-nitro-L-arginine 在体外和体内都抑制 EDRF 的生物合成,是 EDRF 有效拮抗剂。本文研究结果表明 N^G-nitro-L-arginine 和 HCl·N^GO^2-NO_2-L-Arg-OCH_3在体外有血管舒张作用,但是这两个化合物在体内对动脉血压具有剂量依赖的增加效应。在体外 HCl·N^(G-)NO_2-L-Arg-N_G-NO_2-L-Arg-OCH_3对 NE 收缩的鼠动脉肌条有舒张作用,而在体内它具有两向性。例如低剂量时可使大鼠平均动脉血压(MAP)降低,而高剂量时使 MAP 增高。N^G-Tos-L-Arg-N^G-Tos-L-Arg-OH 具有剂量依赖关系的舒血管作用和降低血压的活性。
基金
This project was supported by the Natural Sciences Foundation of Beijing.
