尾核内微量注射一氧化氮前体和供体对大鼠痛行为的影响

Effects of administration of L-arginine and sodium nitroprusside into caudate nucleus on pain behavior of rats

目的观察大鼠尾核内一氧化氮（NO）对动物痛阈（痛行为）的影响.方法以钾离子透入引起大鼠甩尾的电流强度（mA）作为痛反应指标,尾核内微量注射L-精氨酸（L-Arg）、D-精氨酸（D-Arg）、硝普钠（SNP）和血红蛋白（Hb）等,观察0～30min内大鼠痛阈的变化.结果大鼠尾核内微量注射NO的前体L-Arg和供体SNP引起明显的痛敏效应,与对照组比较有显著性差异（P〈0.01或P〈0.05）.微量注射D-Arg、Hb及SNP和Hb的混合液后大鼠痛阈变化30min内与对照组比较无显著性差异（P〈0.05）.结论中枢神经系统内NO水平升高具有明显的痛敏效应,提示大鼠脑内NO在痛觉调制的复杂过程中发挥着重要作用.

Objective： To observe the effect of nitric oxide （NO） on the pain threshold of rats. Methods：The potassium iontophoresis induced tail-flick was used to measure the pain threshold （PT）. The changes were observed by micro-injecting L-arginine（L-Arg）, D-arginine（D-Arg）, sodium nitroprusside （SNP） and hemoglobin （ tab} into rat caudate nucleus in 30 minuts. Results： The significant hyperalgesic effects were observed by micro-injecting L-Arg and SNP into candate nucleus of rats. There were significant differences in the treatment groups （ P 〈 0.01, P 〈 0.05 ）, while the PT of rats showed no changes by micro-injecting D-Arg, lib and the mixed liquid which included SNP and Hb. There were no significant differences in the changes of pain threshold compared with those of NS group in 30 minutes （ P 〈 0.05）. Conclusion：An increase of NO in central nervous system （CNS） produces hyperalgesia, and NO in the brain may be involved in pain modulation.