乙醇对离体大鼠胸主动脉环的舒张作用及其机制  

VASODILATING EFFECT AND ITS MECHANISM OF ETHANOL ON ISOLATED RAT THORACIC AORTA AT DIFFERENT RESTING TENSION

作　　者：茹筱晨[1] 钱令波[1] 崔洁[1] 钱韵[1] 高琴[1] 夏强[1] 

机构地区：[1]浙江大学医学院生理学系,浙江杭州310058

出　　处：《中国应用生理学杂志》2008年第3期269-273,共5页Chinese Journal of Applied Physiology

基　　金：浙江省科技厅基金项目(2005C30026);国家基础科学人才培养基金资助项目(J0710043)

摘　　要：目的:观察不同预张力下乙醇对离体大鼠胸主动脉环舒缩作用的影响及其机制。方法:采用离体血管灌流技术,设置不同预张力,记录乙醇作用下离体大鼠胸主动脉环的张力变化。结果:不同预张力下(1.0、1.5、2.0、2.5、3.0、3.5、4.0g),乙醇(0.1‰、0.2‰、0.5‰、0.8‰、1.5‰、3.0‰、7.0‰。)对由KCl(6×10-2mol/L)或苯肾上腺素(phenylephrine,PE,10-6mol/L)预收缩的去内皮血管环产生舒张作用,其中3g预张力下乙醇舒血管作用最明显;但对内皮完整血管环的舒张作用较弱;在3g预张力下,最大效应浓度(3‰)的乙醇可使由KCl或PE预收缩的去内皮血管环的CaCl2量效曲线下移,最大反应显著降低:在3g预张力下,肌浆网ryanodine受体阻断剂钌红(10-5mol/L)及三磷酸肌醇(trisphosphate inositol,IP3)受体阻断剂肝素(50mg/L)预孵育可减弱乙醇对由PE预收缩的去内皮血管环的舒张作用。结论:乙醇具有不依赖内皮的舒血管作用,3g预张力下舒血管作用最强。乙醇可能通过抑制血管平滑肌细胞膜上电压依从性和受体操作性钙通道,减少外钙内流,以及抑制肌浆网ryanodine受体和IP3受体途径,减少内钙释放而发挥舒血管作用。Aim： To investigate the vasodilating effect and its mechanism of ethanol on isolated rat thoracic aorta at different resting tension. Methods： The tension of the isolated Sprague-Dawley rat thoracic aorta rings perfused with different concentrations of ethanol was measured using organ bath technique. Results： At different resting tension（ 1.0,1.5,2.0,2.5,3.0,3.5 and 4.0 g）, ethanol（0.1- 7.0‰）caused a concentration-dependent relaxation on endothelium-denuded aortic rings precontracted with KCI （6 × 10^-2mol/L）or phenylephrine （PE, 10^-6mol/L） ,and the vasodilating effect was the most potent when the aortic rings were at the resting tension of 3 g. Ethanol had much less vasodilating effect on endothelium-intact aortic rings. Ethanol at 3‰ （the maximum-effect concentration） inhibited the CaCl2 induced contraction and downward shifted concentration-response curve of endothelium-denuded aortic rings precontracted with KCI or PE at the resting tension of 3 g. Incubation of aorta with ruthenium red（10^-5mol/L）or heparin （50 mg/L） decreased the vasodilating effect of ethanol （3.0‰）on endothelium-denuded aorta precontracted with PE at the resting tension of 3 g. Conclusion： Ethanol induces endothelium-independent relaxation on rat thoracic aorta, which is concerned with the resting tension. This effect of ethanol may be mediated by the inhibition of voltage-dependent and receptor-operated Ca^2＋ channels in the vascular smooth muscle cells. The inhibition of the ryanodine receptor and trisphosphate inositol （1P3） pathway may also contribute to this effect.

关 键 词：乙醇 胸主动脉 血管舒张 钙通道 RYANODINE受体 三磷酸肌醇 

分 类 号：R331.3[医药卫生—人体生理学]