酒精对大鼠脑组织内神经甾体的调节机制研究

发布时间：2018-01-14 22:22

本文关键词：酒精对大鼠脑组织内神经甾体的调节机制研究　出处：《河北医科大学》2005年博士论文　论文类型：学位论文

【摘要】：神经甾体特指大脑神经元和胶质细胞合成的甾体,可通过非基因机制作用于中枢GABAA、NMDA 等受体系统,发挥其生理学效应,如镇静催眠、抗焦虑、抗惊厥等。一方面,神经甾体可以抑制小鼠吗啡依赖和耐受的形成,影响大鼠条件性位置偏爱的建立,发挥偏爱或嫌恶作用;还可影响大鼠的饮酒行为,显著降低酒精依赖大鼠摄酒量,增加非酒精依赖大鼠的摄酒量,并能够替代酒精的特定行为效应。另一方面,酒精依赖、戒断可诱发皮质、海马、小脑及血液中部分神经甾体水平变化,改变GABAA受体的功能特性及其对神经甾体的敏感性,使GABAA受体产生适应性,此适应性变化构成了酒精依赖的神经生物学基础,其分子机制可能涉及酒精诱导的细胞表面受体表达、亚细胞定位、突触定位,受体磷酸化,神经甾体水平和GABAA 受体亚基组成等改变。由此推测,酒精依赖可能与大脑特别是奖赏回路各相关核团的内源性神经甾体生物合成有关,内源性神经甾体在酒精依赖与GABAA 受体的相互作用方面发挥着重要作用。有关神经甾体在中枢神经系统中的正常合成与代谢途径已基本阐明。研究表明急性酒精注射可以调节大鼠脑区内神经甾体合成代谢酶甾体快速调节蛋白(StAR)、3β-羟基甾体还原酶(3β-HSD)和3α-羟基甾体还原酶(3α-HSD) 的mRNA 表达;慢性酒精处理可抑制WSP 鼠皮质、海马和杏仁核部位的5α-还原酶活性。慢性酒精处理是否影响伏隔核、杏仁核、腹侧被盖区、纹状体和下丘脑等脑区其它神经甾体合成代谢酶的表达活性未见文献报道。慢性酒精依赖和戒断影响大鼠部分脑区神经甾体的水平,这种变化是否与神经甾体合成代谢酶在中枢神经系统中的表达调控相关尚待证实。本实验采用固相萃取结合液相色谱-质谱联用技术,建立了一种灵敏、准确和特异性强的检测方法,可以满足大鼠脑组织及血浆中微量游离型或硫酸酯型神经甾体的测定需要;采用大鼠酒精依赖和戒断模型,研究大鼠酒精依赖和戒断时不同脑区神经甾体水平的变化;应用免疫组织化学方法,研究胆固醇侧链裂解酶(P450scc)蛋白和GABA_A α1 亚基
[Abstract]:Neurosteroids, specifically the steroids synthesized by neurons and glial cells in the brain, can exert physiological effects, such as sedation and hypnosis, by acting on the central GABA AANMDA receptor system through non-gene mechanisms. On the one hand, neurosteroids can inhibit the formation of morphine dependence and tolerance in mice, affect the establishment of conditioned place preference in rats, play a role of preference or aversion; It can also affect the drinking behavior of rats, significantly reduce the alcohol intake of alcohol dependent rats, increase the alcohol intake of non-alcohol dependent rats, and can replace the specific behavioral effects of alcohol. On the other hand, alcohol dependence. Withdrawal can induce changes in some neurosteroids in cortex, hippocampus, cerebellum and blood, change the functional characteristics of GABAA receptor and its sensitivity to neurosteroids, and make GABAA receptor adaptive. This adaptive change constitutes the neurobiological basis of alcohol dependence and its molecular mechanism may involve the expression of receptors subcellular localization synaptic localization and receptor phosphorylation induced by alcohol. The changes of neurosteroid level and GABAA receptor subunit composition suggest that alcohol dependence may be related to endogenous neurosteroid biosynthesis in the brain, especially in the relevant nuclei of the reward circuit. Endogenous neurosteroids play an important role in alcohol-dependent interactions with GABAA receptors. The normal biosynthesis and metabolic pathway of neurosteroids in the central nervous system (CNS) have been elucidated. Star. MRNA expression of 3 尾 -hydroxysteroid reductase 3 尾 -HSDand 3 伪 -hydroxysteroid reductase 3 伪 -HSDs; Chronic alcohol treatment could inhibit the activity of 5 伪 -reductase in cortex, hippocampus and amygdala of WSP rats. Whether chronic alcohol treatment affected nucleus accumbens, amygdala, ventral tegmental area. The expression activity of other neurosteroid synthase in striatum and hypothalamus has not been reported. Chronic alcohol dependence and withdrawal affect the level of neurosteroids in some brain regions of rats. Whether this change is related to the expression and regulation of neurosteroid synthase in the central nervous system remains to be confirmed. A sensitive, accurate and specific detection method was established by solid phase extraction (SPE) combined with liquid chromatography-mass spectrometry (LC-MS). It can meet the needs of the determination of free or sulfate type neurosteroids in brain tissue and plasma of rats. The changes of neurosteroid levels in different brain regions of rats with alcohol dependence and withdrawal were studied by using the model of alcohol dependence and withdrawal in rats. Study on the protein and GABA_A 伪 1 subunit of cholesterol side chain cleavage enzyme P450 SCC by immunohistochemical method
【学位授予单位】：河北医科大学
【学位级别】：博士
【学位授予年份】：2005
【分类号】：R363

【参考文献】