海洛因依赖大鼠中脑腹侧被盖区和伏隔核内L-ENK和生长抑素表达的变化

目的:探讨海洛因依赖大鼠中脑腹侧被盖区(VTA)和伏隔核(NAc)内亮氨酸脑啡肽(L-ENK)和生长抑素(SS)表达的变化及其可能的机制。方法:成年雄性SD大鼠55只,随机分为正常对照组、盐水对照组及海洛因依赖组。皮下注射海洛因建立海洛因依赖大鼠模型,分别于模型建立的第10、17、24、31、38 d取脑组织,应用免疫组织化学SABC法、图像分析法检测VTA和NAc内L-ENK和SS的表达。结果:海洛因依赖组大鼠VTA和NAc中L-ENK和SS阳性细胞免疫反应明显减弱,与正常及盐水对照组比较有显著性差异(P<0.05);图像分析显示海洛因依赖组L-ENK和SS阳性细胞的平均灰度值增高(P<0.05)。结论:在海洛因依赖期间,大鼠VTA和NAc内L-ENK和SS免疫阳性物质的表达均明显减少,提示海洛因依赖对神经元的神经内分泌功能造成了损伤。

The expressional change of L-ENK and somatostatin in the ventral tegmental area and nucleus accumbens of heroin dependent rat

Objective:To investigate the expressional change of L-ENK,somatostatin(SS) immunoreactivities in ventral tegmental area(VTA) and nucleus accumbens(NAc) neurons in heroin dependence rat,and the possible mechanisms.Methods: 55 adult male SD rats were randomly divided into normal control group,saline control group and heroin dependent group.Rats were chronically treated by injection of heroin for up to 38 d,and brain tissues was removed on 10,17,24,31,38 days after models set up,respectively.Immunohistochemical SABC method,image analysis were performed to test the expression of L-ENK and SS in the VTA and NAc regions.Results: Comparing with normal control group and saline control group,the expression of L-ENK-and SS-immunoreactivities were obviously decreased in the VTA and NAc regions in heroin dependent group,and there was statistical significance(P<0.05).Image analysis showed that grey value of L-ENK-and SS-immunoreactive neurons increased in heroin dependent groups than that in two control groups(P<0.05).Conclusions: The expression of L-ENK-and SS-immunoreactivities decrease in the VTA and NAc regions during heroin dependent,indicating heroin dependent may cause the neuroendocrine functional damage in the neurons.