低浓度乙醇对大鼠血管内皮损伤的保护作用

目的研究低浓度乙醇对低密度脂蛋白(LDL)诱导的血管内皮损伤的保护作用与内源性一氧化氮合酶抑制物的关系。方法SD大鼠在乙醚麻醉下,舌下静脉注射人血清LDL(4mg/kg)诱发血管内皮功能损伤。检测血中非对称性二甲基精氨酸(ADMA)、丙二醛(MDA)和一氧化氮(NO)的含量,并观察离体胸主动脉环的内皮依赖性舒张反应。结果单次静注LDL(4mg/kg)显著抑制乙酰胆碱(ACh)诱导的内皮依赖性舒张,增加血液中ADMA和MDA,降低NO水平。低浓度乙醇(10%,4ml/kg)能显著减轻LDL所致ACh诱导内皮依赖性舒张的损伤,能显著抑制ADMA和MDA浓度升高,降低NO浓度。但其他浓度乙醇(5%、15%,4ml/kg)对ADMA和NO浓度有较小的影响。结论低浓度乙醇对LDL诱导的血管内皮细胞损伤有保护作用,其保护作用与降低ADMA浓度有关。

Protective effect of alcohol at low dose against damages of the endothelium in rats

Objective To study the protective effect of alcohol against damages of the endothelium induced by Low-density lipoprotein(LDL),and relation between the protective effect of alcohol and the reduction of nitric oxide synthase inhibitor level.Methods Vascular endothelial injury was induced by a single injection of native LDL(4 mg/kg)in rats.Blood samples were collected from carotid artery.Vasodilator responses to acetylcholine(ACh)in the isolated aortic rings were determined,and the serum concentrations of asymmetric dimethylarginine(ADMA),malondialdehyde(MDA)and nitric oxide(NO)were measured.Results A single injection of LDL(4 mg/kg)significantly decreased vasodilator responses to ACh,increased the serum level of ADMA,MDA,and decreased the serum level of NO.10% alcohol(4 ml/kg)markedly reduced the inhibition of vasodilator responses to ACh by LDL,and inhibited the increased level of ADMA and MDA,and inhibited the decreased concentration of NO by LDL.5% and 15%alcohol(4ml/kg)had lower effect on the concentration of ADMA and NO.but increased the concentration of MDA by LDL.Conclusion Alcohol at the lower concentration protects the endothelium against damages elicited by LDL in vivo,and the protective effect of alcohol on endothelium is related to reduction of ADMA concentration.