血管加压素对酒精戒断大鼠下丘脑-腺垂体-肾上腺皮质功能的影响

目的:观察在长期低浓度酒精处理及酒精戒断过程中,大鼠血浆中血管加压素(AVP)、促肾上腺皮质激素(ACTH)和皮质醇含量的变化以及下丘脑中AVP、促肾上腺皮质激素释放因子(CRF)含量的变化,进而探讨酒精对机体应激水平的影响以及AVP在酒精依赖过程中的作用。方法:以6%(V/V)的酒精作为大鼠饮水的唯一来源,分别饮酒1、3、7、14、21、28d,以及饮酒28d后撤除酒精2h,取不同处理大鼠的血浆和下丘脑标本,采用放射性免疫测定法分别测定CRF、AVP、ACTH和皮质醇水平;气相色谱法测定大鼠在饮酒过程中不同时段血中酒精浓度。结果:大鼠饮酒3d后,血浆中的AVP和皮质醇水平显著增高,并持续至饮酒结束,而血浆ACTH水平无明显变化。使用AVP受体拮抗剂后,血液中ACTH和皮质醇含量显著下降。动物血中酒精浓度在摄入酒精的不同时段无明显差异。结论:长时程的低浓度酒精刺激使机体应激水平升高,同时下丘脑-腺垂体-肾上腺皮质轴功能紊乱,这可能是动物产生酒精依赖的重要原因之一。

Effects of vasopressin on the function of hypothalamic-pituitary-adrenal in the rats with drawn from ethanol

Objective:To investigate the effects of the chronic exposure to ethanol on the animal stress and the role of vasopressin(AVP)in ethanol dependence in the rats.Methods:Rats were fed with low concentration of ethanol(6%,v/v)for 1,3,7,14,21,or 28 d respectively.The samples of plasma and hypothalamic tissue from the rats of different groups were taken for analysis.The level of AVP,cortisone,and adrenocorticotropin(ACTH)in plasma or the concentration of hypothalamic AVP and corticotropin-releasing factor(CRF)were measured by radioimmunoassay(RIA).The ethanol concentration in blood was measured by headspace gas chromatography.Results:The level of ACTH in plasma remained unchanged when the rats were exposed to ethanol,but the levels of vasopressin and cortisone in plasma were increased.Intracerebroventricular injection of AVP V1 receptor antagonist could significantly reduce ACTH and cortisone content in plasma.The ethanol concentration in blood had no changes during the periods of exposure to ethanol.Conclusion:The alterations of the plasma AVP and cortisone may result from the chronic and repeated exposure to low concentration of ethanol.The disorders of the hypothalamic-pituitary-adrenal function may be essential for the psychological dependence in the rats.