依那普利对大鼠离体胸主动脉的舒张作用及其机制

目的：观察依那普利对血管的直接作用，并探讨其机制。方法：采用Powerlab生物信号采集系统记录依那普利对去甲肾上腺素（NE）和KCl预收缩的离体大鼠胸主动脉环舒张作用，观察左旋硝基精氨酸甲酯（L—NAME，10^-4mol／L）和吲哚关辛（10^-8mol／L）对其作用的影响。结果：在内皮完整的大鼠离体胸主动脉环，依那普利（10^-9～10^-4mol／L）对NE（10^-5mol／L）或KCl（20mmol／L）引起的收缩具有浓度依赖性的舒张作用。去内皮后，依那普利的舒血管作用显著减弱。在内皮完整的血管环，L—NAME（10^-4mol／L）和吲哚美辛（10^-8mol／L）对依那普利的舒血管作用具有明显的抑制作用。结论：依那普利对大鼠离体胸主动脉环具有浓度依赖性的舒张作用，此作用具有内皮依赖性，与内皮产生的NO和前列环素（PGI2）有关。

Vasodilative effect and mechanism of enalapril on thoracic aorta of rats

AIM： To investigate the vasodilative effects and the possible mechanism of enalapril on thoracic aorta of rats. METHODS： Isotonic tension of thoracic aortic rings precontracted by norepinephrine （NE, 10^-5 mol/L） or KCl （20 mmol/L） was recorded. The vascular tension was recorded by Powerlab multichannel physiology signal acquisition and analysis computer system by tension transducers. The vasorelaxing action of enalapril and effects of various drugs which include NG-nitro-L-arginine methyl ester （10^-4mol/L） and indomethacin （10^-8 mol/L） were observed in the rings with endothelium intact or denuded. RFSULTS： Enalapril （ 10^-9 - 10^-4 mol/L） induced concentrationdependent relaxation in thoracic aortas with intact endothelium. There was significant difference between the rings with intact and denuded endothelium. N^G-nitro- L-arginine methyl ester （ 10^-4 mol/L） and indomethacin （ 10^-8 tool/L） can signifi effects of enalapril on thoracic SION： We conclude that cant inhibit the relaxtion aortic rings. CONCLUenalapril preferentially antagonized the contraction of rat thoracic artery in a concentration-dependent and The vasorelaxation of duction of nitric oxide and prostacyclin.