IN VITRO MODELS FOR ETHANOL EFFECTS ON RECEPTOR-MEDIATED PROCESSES

我们工作的一个主要重点是评估急性和非传染性疾病 酒精对中枢神经系统的慢性影响。然而，大脑代表着一种 不同类型的细胞集合，并区分直接和 乙醇的间接影响可能很难实现。体外细胞培养 系统可用于监测乙醇的特定、直接影响，如 与脑组织中的结果进行比较和对比 活着。乙醇对大鼠脑内NMDA受体影响的研究现状 小脑颗粒细胞的原代培养现已在 项目AA00706。此外，5-羟色胺(5-HT-3)的研究 NCB20体细胞杂交中的受体正在进行中，并正在 基于以下发现：1)乙醇增强激动剂的作用 5-羟色胺-3受体在NCB20细胞电生理研究中的作用 2)5-羟色胺-3受体拮抗剂阻断辨别性刺激 乙醇的性质(见项目AA00707)。以确定是否 乙醇直接影响配体与5HT-3的相互作用 与这些受体结合的受体、拮抗剂和激动剂 通过过滤器结合技术进行评估。拮抗剂~3H-GR65630， 与NCB20膜上单一位点结合的激动剂(5-羟色胺，2-Me-5羟色胺) 位移曲线用单点模型拟合最好。乙醇(12.5- 100 mM)对激动剂或拮抗剂均无显著影响 结合，并可能相反地影响受体-效应器耦合过程。 行为学研究表明，乙醇在5HT-3中的作用 受体在调节乙醇的主观效应中很重要(例如， 强化、中毒)和对培养细胞的研究可能会提示 这些体内反应背后的生化机制。

A major focus of our work involves an evaluation of the acute and chronic effects of ethanol in the CNS. However, the brain represents a heterogeneous collection of cell types, and distinction of direct and indirect effects of ethanol can be difficult. In vitro cell culture systems can be used to monitor specific, direct effects of ethanol, for comparison and contrast with results obtained in brain tissue and in vivo. Current studies of the effect of ethanol on NMDA receptors in primary cultures of cerebellar granule cells are now described in project AA00706. In addition, investigations of serotonin (5HT-3) receptors in NCB20 somatic cell hybrids are being performed, and are based on the findings that 1) ethanol enhances the action of agonists at the 5HT-3 receptor in electrophysiological studies of NCB20 cells, and 2) 5HT-3 receptor antagonists block the discriminative stimulus properties of ethanol (see Project AA00707). To determine whether ethanol directly affects the interaction of ligands with the 5HT-3 receptor, antagonist and agonist binding to these receptors were assessed by filter binding techniques. The antagonist, 3H-GR65630, bound to a single site on NCB20 membranes, and agonist (5HT, 2-Me-5HT) displacement curves were best fit by a one-site model. Ethanol (12.5 - 100 mM) had no significant effect on either agonist or antagonist binding, and may instead affect receptor-effector coupling processes. The behavioral studies suggest that the action of ethanol at the 5HT-3 receptor is important in mediating subjective effects of ethanol (e.g., reinforcement, intoxication) and studies in cultured cells may suggest a biochemical mechanism underlying these in vivo responses.