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利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 阿片类药物耐受的潜在机制(S)仍有待阐明。神经肽FF(NPFF，Phe-Leu-Phe-Gln，Pro-Gln，Arg，Phe-NH2)是一种哺乳动物八肽，已被证明可减弱阿片类药物诱导的多种效应，如抗伤害性感觉和吗啡耐受和依赖的形成。据推测，吗啡的使用释放了抗阿片剂，这是体内平衡机制的一部分。随着吗啡用量的增加，越来越多的抗阿片类药物被释放到脑脊液中。直接的结果是，MU阿片受体(MOR)复合体下调，产生越来越高程度的激动剂亚敏感性(耐受性)。本项目将探讨NPFF通过解偶联G蛋白和/或改变NPFF和MOR之间共享的信号转导途径来减弱吗啡诱导的耐受的机制(S)。慢性(13天)脑室注射硫酸吗啡，通过阿尔赛特2001渗透压迷你泵，使大鼠耐受。因为之前的研究结果表明慢性丙型肝炎病毒。单独注射吗啡和NPFF能够下调吗啡浓度，本提案是进一步研究NPFF减轻脊髓和与阿片类药物耐受相关的不同脑区(大脑皮层、纹状体和丘脑)吗啡耐受机制的极佳模型(S)。为了验证这一假说，将通过与MOR信号转导途径相关的几个指标(GTP-伽马-S活性、cAMP水平、蛋白激酶A和C活性)来测试NPF对吗啡耐受性的慢性影响。其他实验将确定在MOR受体密度下NPFF的调节是否与MOR和NPFF受体蛋白的转录水平和/或表达的变化有关。这些发现有望通过更清楚地了解吗啡耐受在MOR系统的信号转导通路中的位置，从而阐明NPF减轻吗啡耐受的机制(S)。

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.