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

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.

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

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(Hb) into rat caudate nucleus in 30 minuts.Results:The significant hyperalgesic effects were observed by micro-injecting L-Arg and SNP into caudate 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 microinjecting D-Arg,Hb 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.