FUNCTIONAL SIGNIFICANCE OF MU OPIOID RECEPTOR TURNOVER

这是一项科学家发展奖(K21)的申请。在中国的研究 这项建议旨在确定穆阿片类药物之间的关系 受体周转对阿片类药物生化和药理指标的影响 受体功能。阿片受体与神经递质关系的研究 阿片受体的生化和药理指标与占有率 函数与理解决定 阿片类药物在整个动物中的效力和疗效。初步数据显示 当大鼠脑内Mu阿片受体密度降低时 通过与β-FNA(β-FNA)受体烷基化， 海洛因回流前的强化效应 受体结合的回归。这些数据表明，Mu-阿片受体 应同时使用生化和药理学方法来衡量周转 受体功能的分析，而不是仅作为受体结合的指标 受体周转率。这项研究的目的是确定 用受体结合力测定Mu阿片受体周转的相关性 或受体功能的生化分析(腺酰环化酶抑制 和GTP酶的刺激)对Mu-阿片激动剂的体内效应。 特定目标1验证了以下假设： 当相对较小比例的阿片类药物在整个动物体内恢复时 MU-阿片受体与G-蛋白发生功能偶联。时间 β-FNA i.c.v的作用过程。关于Mu受体介导的研究 我们将比较GTP酶的刺激作用和腺苷环化酶的抑制作用 对吗啡镇痛和运动亢进的影响。这个 第二个特定的目标是检验u=阿片受体周转的假设 在与药物相关的大脑区域更快，而且 受体结合实验不能确定这一点，因为事实是 这些受体种群在这些受体中所占的比例相对较小 在整个大脑中。将检验这一假设的实验是 与特异靶向1中类似，除了数量受体 放射自显影将被用来评估u-阿片受体的密度。 在受体烷基化后的离散脑区。第三 特定的目的验证了受体烷基化将导致 与药物相关的受体生物合成的上调 大脑的不同区域。受体烷基化后，Mu-阿片受体 在不同的时间点，不同脑区的mrna会被定量。 并与吗啡的回归药理作用进行比较。 特异靶4验证了阿片受体抑制的假设 生物合成将是改变药理效应的最有效方法 当阿片类药物注射到相关大脑区域时，会产生大量的阿片类药物。这些 实验将包括注射反义寡核苷酸来治疗 MU-阿片受体mRNA进入含有最高含量的大脑区域 MU-阿片受体mRNA的表达，或其中的mRNA增加到 受体烷基化后的最大幅度。

This is a request for a Scientist Development Award (K21). The research in this proposal is designed to determine the relationship of mu-opioid receptor turnover to biochemical and pharmacological indices of opioid receptor function. Investigating the relationship of opioid receptor occupancy with biochemical and pharmacological indices of opioid receptor function is pertinent for understanding the mechanisms that determine the potency and efficacy of opioids in whole animals. Preliminary data suggest that when the density of mu-opioid receptors is decreased in rat brain through receptor alkylation with beta-funaltrexamine (beta-FNA), the reinforcing effects of heroin return prior to the return prior to the return of receptor binding. These data suggest that mu-opioid receptor turnover should be measured using both biochemical and pharmacological assays of receptor function, rather than receptor binding alone as indices of receptor turnover. The objective of this research is to determine the relevance of mu-opioid receptor turnover as measured with receptor binding or biochemical assays of receptor function (inhibition of adenylyl cyclase and stimulation of GTPase) to the in vivo effects of mu-opioid agonists. Specific aim 1 tests the hypothesis that the pharmacological activity of opioids in whole animals is restored when a relatively small proportion of mu-opioid receptors become functionally coupled to G-proteins. The time course of the effects of beta-FNA i.c.v. on mu-receptor-mediated stimulation of GTPase and inhibition of adenylyl cyclase will be compared to the effects on morphine-induced analgesia and hyperlocomotion. The second specific aim tests the hypothesis that mu=opioid receptor turnover is more rapid in pharmacologically-relevant brain regions, and that receptor binding experiments do not determine this due to the fact that these receptor populations represent a relatively small proportion of those in the whole brain. The experiments that will test this hypothesis are similar to those in specific aim 1, except that quantitative receptor autoradiography will be used to assess the density of mu-opioid receptors in discrete brain regions following receptor alkylation. The third specific aim tests the hypothesis that receptor alkylation will result in an upregulation of receptor biosynthesis in pharmacologically-relevant regions of the brain. Following receptor alkylation, mu-opioid receptor mRNA will be quantitated in various brain regions at different time points and compared to the return of the pharmacological effects of morphine. Specific aim 4 tests the hypothesis that inhibition of mu-opioid receptor biosynthesis will be most effective at altering the pharmacological effects of opiates when administered into relevant brain regions. These experiments will involve administering anti-sense oligodeoxynucleotides for mu-opioid receptor mRNA into brain regions that contain the highest amount of mu-opioid receptor mRNA or in which the mRNA is increased to the greatest extent following receptor alkylation.