OPIOIDS & DESENSITIZATION TO SUBSTANCE P INSPINAL CORD

重复鞘内（i.t.）在小鼠中注射SP导致 “脱敏”或减少对SP的行为反应。我们的研究 表明对SP行为效应的脱敏依赖于 对SP的N-末端代谢片段和兴奋性 氨基酸（EAA）活性。 所提出的实验将进一步测试 SP N端代谢产物通过调节痛觉 抑制伤害感受性递质的释放以及其作用， 脊髓，部分通过与μ-型阿片样物质直接相互作用 受体。 目的1：制备抗N-末端的单克隆抗体 SP片段，并将其用于RIA和潜在的药理学 拮抗剂在体内检查SP片段在脊髓中的作用。 目的2：我们将评估SP片段调节细胞凋亡的能力。 用在体微透析法测定脊髓栓中SP的释放 清醒的，自由移动的大鼠，以监测N-和C-末端的影响 SP片段对KCl或伤害性感受诱导的 SP和EAA的浓度。 我们将确立鸦片制剂的作用 受体在这种调节使用选择性阿片拮抗剂。 目的 3：我们将继续表征N-末端SP上的结合位点 通过确定SP代谢物是否与 仅与μ 1型阿片样物质结合位点结合，或者它们是否也 与不同位点相互作用，不同于mu 1或SP。 然后将在足底注射以下物质后在小鼠中检查结合： 弗氏佐剂，以确定疼痛是否由SP N- 末端结合 目的4：我们将使用 放射自显影技术，以观察结合是否差异定位 在大脑和脊髓中， 特别是在被认为与疼痛传播有关的区域， 已知含有SP（1-11）样免疫反应性的区域。 目标5：我们 将决定是否对i.t. SP 或N-甲基-D-天冬氨酸（NMDA）或对红藻氨酸或使君子酸的致敏作用 使用热板和扭体试验改变伤害感受。 阿片 拮抗剂将用于确定阿片类药物或其受体是否 参与任何检测到的变化。

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.