CHARACTERIZATION OF NICOTINE RECEPTORS

虽然尼古丁在中枢神经系统产生不同的药理作用， 在神经系统中，关于烟碱的亚型知之甚少。 负责调节尼古丁不同作用的受体。 这项提案的主要目标是了解神经元的功能， 烟碱受体和建立各种烟碱受体的作用 亚基的药理作用，尼古丁在中枢神经系统中使用这两个 in vivo体内and in vitro体外approaches方法. 我们建议继续我们的结构- 活动关系研究提供了有趣的结果， 扩大我们目前的类似物系列，并继续与几个新的 举措 类似物将在几个体内评价 （小鼠的抗伤害感受和运动功能减退以及大鼠的药物辨别） 和体外（3（H）-尼古丁和125 I-α-BGTX结合）测定， 尼古丁样效应 有趣的类似物将在青蛙中进行评估 表达不同烟碱受体亚单位的卵母细胞，以证实 体内和体外结果。 这种方法应该为我们提供新的 具有更高选择性和独特特征的化合物， 区分负责介导不同的 尼古丁的作用。 我们计划验证脊髓烟碱 受体与神经节和大脑中的受体不同， 鞘内（i.t.）和i. c. v. 局 此外，我们还将确定 选择性烟碱拮抗剂在i.t.和 i. c. v.给药。 此外，我们将确定一些 脱敏和耐受的潜在机制， 和体内方法。 体外受体的比较 脱敏和在体内观察到的“脱敏”过程将是 执行。 与之相关的脱敏率和程度 不同烟碱激动剂对神经元烟碱乙酰胆碱受体的作用 将比较非洲爪蟾卵母细胞中表达的亚基组合 用不同烟碱类化合物获得的体内“脱敏”， 在动物中施用的激动剂。 最后，我们将调查 烟碱受体的内在活性在产生 对几种慢性输注后的抗伤害效应的耐受性 对[（3）H]-烟碱具有广谱亲和性的烟碱激动剂 结合位点。 这些研究将有助于了解 神经元烟碱受体和建立各种烟碱的作用， 受体亚单位在尼古丁的药理作用。

Although nicotine produces diverse pharmacological effects in the central nervous system, relatively little is known regarding subtypes of nicotinic receptors responsible for mediating the different actions of nicotine. The broad goal of this proposal is to understand the function of neuronal nicotinic receptors and establish the role of various nicotinic receptors subunits in the pharmacological effects of nicotine in the CNS using both in vivo and in vitro approaches. We propose to continue our structure- activity relationship studies which are providing intriguing results and expand our current series of analogs as well as proceed with several new initiatives. Analogs will be evaluated in several in vivo (antinociception and hypomotility in mice and drug discrimination in rats) and in vitro (3(H)-nicotine and 125I-alpha-BGTX binding) assays for nicotine-like effects. Interesting analogs will be evaluated in frog oocytes expressing different nicotinic receptor subunits to corroborate in vivo and in vitro findings. This approach should provide us with novel compounds with greater selectivity and unique profiles to be used for distinguishing receptor subtypes responsible for mediating the different actions of nicotine. We plan to test the hypothesis that spinal nicotinic receptors differ from those in ganglia and brain by studying the SAR for nicotinic receptor activation after intrathecal (i.t.) and i.c.v. administration. In addition, we will determine the effectiveness of selective nicotinic antagonists to block these agonists after i.t. and i.c.v. administration. Furthermore, we will determine some of the mechanisms underlying desensitization and tolerance using both in vitro and in vivo approaches. A comparison between in vitro receptor desensitization and the 'desensitization' process observed in vivo will be performed. The rate and extent of desensitization associated with different nicotinic agonists on neuronal nicotinic acetylcholine receptor subunit combinations expressed in Xenopus laevis oocytes will be compared with the in vivo "desensitization" obtained with different nicotinic agonists administered in animals. Finally, we will investigate the importance of intrinsic activity of nicotinic receptors in producing tolerance to the antinociceptive effect after chronic infusion of several nicotinic agonists with a wide spectrum of affinity for [(3)H]-nicotine binding sites. These studies will help to understand the function of neuronal nicotinic receptors and establish the role of various nicotinic receptors subunits in the pharmacological effects of nicotine.