GENETIC CONTROL OF RESPONSIVENESS TO N20 ANTIOCICEPTION

描述：（申请人摘要） 一氧化二氮（N20）镇痛的机制仍然不确定，尽管 对小鼠的研究表明， 受体和一氧化氮（N 0）。 差异反应性近交系C57 BL/6 和DBA/2小鼠对N20的抗伤害作用已引起人们的关注， N 0在N20的作用，初步研究的结果表明， N 0在这些菌株之间起作用。 C57 BL/6小鼠对N20有反应 N20处理后N 0合酶（NOS）活性增加 暴露，但DBA/2小鼠反应差，并没有显示出这种增加， NOS活性。 对N20抗伤害感受的敏感性降低持续存在， 来自C57 BL/6的某些BXD重组近交系（R1）， DBA/2祖细胞。 对BXD RI数据的分析已经确定了临时 数量性状基因座（QTL）或含有等位基因的染色体位点， 影响对N20抗伤害感受反应。 具体目标是 本研究的目的是：（1）比较NO在N20抗伤害作用中的作用， 通过确定N20反应如何受到选择性 在C57 BL/6小鼠中和通过NO负荷抑制神经元NOS与内皮NOS 在DBA/2小鼠中;（2）通过比较C57 BL/6和DBA/2小鼠中NOS功能， 测量脑中[14 C] L-精氨酸向[14 C] L-瓜氨酸的转化 幼稚和N20暴露的C57 BL/6和DBA/2小鼠的区域和脊髓; (3)比较NO在N20诱导的神经元阿片样物质释放中的作用 通过测定NOS抑制对N20保护的影响， （4）鉴定与N20相关的QTL 通过测定B6 D2 F2小鼠对N20的反应性和 使用全基因组扫描进行基因分型;以及（5）确定相关性 B6 D2 F2小鼠的抗伤害感受反应性与其局部 脑和脊髓NOS活性水平。 将使用的方法 包括：抗伤害性试验; NOS测定;阿片样物质 放射性配体结合;和多态性遗传标记的PCR扩增。 这项研究的结果将确定为什么C57 BL/6和DBA/2小鼠 对N20的反应不同，有助于确定特定的基因和作用， NOS和NO在镇痛和麻醉药物作用中的作用。 这项工作 也将有助于更好地了解人类的变异性， 对N20的反应。

DESCRIPTION: (Applicant's Abstract) The mechanism of nitrous oxide (N20) analgesia remains uncertain, although research in mice has implicated an involvement of both kappa-opioid receptors and nitric oxide (N0). Differential responsiveness inbred C57BL/6 and DBA/2 mice to N20 antinociception has focused attention on the role of N0 in N20 action, and results of preliminary studies suggest a difference in N0 function between these strains. C57BL/6 mice are responsive to N20 antinociception and show increased N0 synthase (NOS) activity after N20 exposure, but DBA/2 mice are poorly responsive and show no such increase in NOS activity. The reduced sensitivity to N20 antinociception persists in certain BXD recombinant inbred (Rl) strains derived from the C57BL/6 and DBA/2 progenitors. Analysis of the BXD Rl data has identified provisional quantitative trait loci (QTL) or chromosome sites containing alleles that influence antinociceptive responsiveness to N20. The specific aims of this research are to: (1) compare the role of NO in N20 antinociception in the progenitors by determining how the N20 response is affected by selective inhibition of neuronal vs. endothelial NOS in C57BL/6 mice and by NO loading in DBA/2 mice; (2) compare NOS function in C57BL/6 and DBA/2 mice by measuring conversion of [14C]L-arginine to [14C]L-citrulline in brain regions and spinal cords of naive and N20-exposed C57BL/6 and DBA/2 mice; (3) compare the role of NO in N20-induced neuronal release of opioid peptides by determining the influence of NOS inhibition on N20 protection against alkylation of opioid receptors; (4) identify QTL associated with N20 antinociception by determining responsiveness of B6D2F2 mice to N20 and genotyping using a whole genome scan; and (5) ascertain the correlation between antinociceptive responsiveness of B6D2F2 mice and their regional brain and spinal cord NOS activity levels. Methods to be utilized will include the following: antinociceptive testing; NOS assay; opioid radioligand binding; and PCR amplification of polymorphic genetic markers. The results of this research will determine why C57BL/6 and DBA/2 mice respond differently to N20 and help to identify specific genes and the roles played by NOS and NO in analgesic and anesthetic drug effects. This work will also contribute better understanding of the variability in human responsiveness to N20.