OPIOIDS & DESENSITIZATION TO SUBSTANCE P INSPINAL CORD

重复鞘内注射(I.T.)在小鼠体内注射SP会导致 对SP的“脱敏”或行为反应减弱。我们的研究 提示SP对行为效应的脱敏作用是依赖的 P物质N端代谢片段的积累与兴奋性 氨基酸(EAA)活性。拟议中的实验将进一步测试 SP N-末端代谢物通过调节痛觉的假说 抑制伤害性递质的释放及其作用 脊髓，部分是通过与MU型阿片类药物的直接相互作用 感受器。目的1：制备抗N-末端的单抗 SP片段及其在RIA中的应用和作为潜在的药理作用 在活体内检测SP片段在脊髓中的作用。 目标2：我们将评估SP片段调节 微透析法在大鼠脊髓软塞区释放SP的实验研究 清醒、自由活动的大鼠监测N-末端和C-末端的作用 KCI或伤害性刺激引起的大鼠脑内P物质片段的变化 SP和EaS的浓度。我们将确立阿片剂的作用 受体在此调节中使用选择性阿片类拮抗剂。客观化 3：我们将继续鉴定N-末端SP上的结合位点(S) 通过确定SP代谢物是否相互作用来确定中枢神经系统中的片段 仅与MU1类阿片结合位点或它们是否也 与不同的部位(S)相互作用，这是MU1或SP所独有的。 然后在小鼠的足底注射后检查结合情况 弗洛因德佐剂以确定疼痛是否由SP N的变化引起- 终端绑定。目标4：我们将使用以下工具检查N-末端SP绑定 放射自显影技术，以确定结合是否存在差异定位 在大脑和脊髓内，并量化结合密度 地点，特别是在被认为涉及疼痛传递和 已知含有SP(1-11)样免疫反应的区域。目标5：我们 将决定是否对信息技术的行为影响脱敏。服务提供商 或N-甲基-D-天冬氨酸(NMDA)或对红藻氨酸或奎斯奎因的增敏 使用热板和扭动试验改变伤害感。鸦片类药物 拮抗剂将用于确定其受体的阿片类药物是否 涉及检测到的任何更改。

Repeated intrathecal (i.t.) injections of SP in mice leads to a "desensitization" or decreased behavioral response to SP. Our research suggests that desensitization to the behavioral effects of SP is dependent on an accumulation of N-terminal metabolic fragments of SP and excitatory amino acid (EAA) activity. The experiments proposed will further test the hypothesis that N-terminal metabolites of SP regulate pain perception by inhibiting the release as well as the effect of nociceptive transmitters in the spinal cord, in part, by a direct interaction with mu-type opioid receptors. Objective 1: We will raise monoclonal antibodies to N-terminal fragments of SP and use them in RIAs and as potential pharmacologic antagonists in vivo to examine the role of SP fragments in the spinal cord. Objective 2: We will assess the ability of SP fragments to regulate the release of SP in the spinal cork by using in vivo microdialysis in the conscious, freely-moving rat to monitor the effects of N- and C-terminal fragments of SP on KCI- or nociception-induced changes in the concentrations of SP and EAAs. We will establish the role of opiate receptors in this regulation using selective opiate antagonists. Objective 3: We will continue to characterize the binding site(s) on N-terminal SP fragment in the CNS by determining whether SP metabolites interact exclusively with mu1-type opioid binding sites or whether they also interact with distinct site(s), unique from that of either mu1 or SP. Binding will then be examined in mice after an intraplantar injection of Freund's adjuvant to determine whether pain result from a change in SP N- terminal binding. Objective 4: We will examine N-terminal SP binding using autoradiographic techniques to see if binding is differentially localized within the brain and spinal cord and to quantify the density of binding sites, especially in areas thought to be involved in pain-transmission and areas known to contain SP(1-11)-like immunoreactivity. Objective 5: We will determine whether desensitization to the behavioral effects of i.t. SP or N-methyl-D-aspartate (NMDA) or sensitization to kainate or quisqualate alters nociception using the hot plate and writhing assays. Opiate antagonists will be used to determine whether opioids of their receptor are involved in any changes detected.