NEUROSCIENCE - SUBPROJECT 1: MODULATION OF MORPHINE TOLERANCE BY ANTI-OPIATE PEP

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 阿片类药物耐受的潜在机制仍有待阐明。 神经肽FF（Neuropeptide FF，NPFF，Phe-Leu-Phe-Gln，Pro-Gln，Arg，Phe-NH 2）是一种哺乳动物八肽，具有减轻阿片诱导的多种效应，如抗伤害感受和吗啡耐受性和依赖性。 据推测，吗啡给药释放抗阿片类药物作为体内平衡机制的一部分。 当给予更大量的吗啡时，越来越多的抗阿片剂被释放到脑脊液中。作为直接结果，μ阿片样物质受体（莫尔）复合物被下调，产生逐渐更高程度的激动剂次敏感性（耐受性）。本项目将研究NPFF通过G蛋白解偶联和/或改变NPFF和莫尔之间共享的信号转导途径来减弱吗啡诱导的耐受的机制。 通过Alzet 2001渗透微型泵，通过慢性（13天）脑室内输注硫酸吗啡使大鼠耐受。 因为先前的发现已经表明，单独的吗啡和NPFF的慢性i. c. v.输注能够下调莫尔密度，所以本发明的提议代表了进一步检查NPFF减弱脊髓和离散脑区域（大脑皮层、纹状体和丘脑）中与阿片耐受性相关的吗啡耐受性的机制的极好模型。 为了检验这一假设，将进行研究以检验NPFF对吗啡耐受性的长期作用，如在与莫尔信号转导途径相关的几个指数（GTP-γ-S活性、cAMP水平、蛋白激酶A和C活性）处测量的。 另外的实验将确定莫尔受体密度下的NPFF调节是否与转录水平和/或莫尔和NPFF受体蛋白表达的变化相关。这些发现通过提供关于在莫尔系统的信号转导途径内发生相互作用的更清楚的理解，预期描绘NPFF减弱吗啡耐受的机制。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The underlying mechanism(s) of opiate tolerance remains to be elucidated. Neuropeptide FF (NPFF, Phe-Leu-Phe-Gln,Pro-Gln,Arg,Phe-NH2), is a mammalian octapeptide that has been shown to attenuate various opiate-induced effects, like antinociception and the development of morphine tolerance and dependence. It is hypothesized that the administration of morphine releases anti-opiates as part of a homeostatic mechanism. As greater quantities of morphine are administered, increasing quantities of anti-opiates are released into the cerebral spinal fluid. As a direct consequence mu opioid receptor (MOR) complex is down-regulated, producing progressively higher degrees of agonist subsensitivity (tolerance). The present project will examine the mechanism(s) by which NPFF attenuates morphine-induced tolerance via uncoupling of the G protein and/or altering a shared signaling transduction pathway between NPFF and MOR. Rats will be made tolerant by chronic (13 days) intraventricular infusion of morphine sulfate, via the Alzet 2001 osmotic mini-pumps. Because previous findings have shown that chronic i.c.v. infusion of morphine and NPFF alone were able to down-regulate MOR density, the present proposal represents an excellent model to further examine the mechanism(s) by which NPFF attenuates morphine tolerance in spinal cord and discrete brain regions (Cerebral Cortex, Striatum, and Thalamus) that are associated with opiate tolerance. To test this hypothesis, studies will be conducted to test the chronic effects of NPFF on morphine tolerance as measured at several indices related to the MOR signaling transduction pathway (GTP-gamma-S activity, cAMP levels, protein kinases A and C activities). Additional experiments will determine if NPFF modulation at the MOR receptor density is associated with changes at the transcriptional level and/or expression of MOR and NPFF receptor protein. These findings are expected to delineate the mechanism(s) by which NPFF attenuates morphine tolerance by providing a clearer understanding as to where the interaction is occurring within the signaling transduction pathway of the MOR system.