Vasodilative effect and mechanism of enalapril on thoracic aorta of rats

Abstract

Abstract: 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 (20mmol/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. RESULTS:Enalapril (10^-9 -10^-4mol/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^-4mol/L) and indomethacin (10^-8mol/L) can significant inhibit the relaxtion effects of enalapril on thoracic aortic rings. CONCLUSION:We conclude that enalapril preferentially antagonized the contraction of rat thoracic artery in a concentration-dependent and endothelium-dependent manner. The vasorelaxation of enalapril is relevant to the production of nitric oxide and prostacyclin.

Key words: enalapril, thoracic aorta, vasodilation, endothelium, nitric oxide, prostacyclin

CLC Number:

R965.2

WANG Dan, ZHANG Xuan-ping, DONG Qiu-ju, ZHANG Ming-sheng, NIU Long-gang, CHANG Hai-liang. Vasodilative effect and mechanism of enalapril on thoracic aorta of rats[J]. Chinese Journal of Clinical Pharmacology and Therapeutics, 2008, 13(2): 149-153.

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