Duan J, Sawynok J
Neuropharmacology. 1987 Apr;26(4):323-9. doi: 10.1016/0028-3908(87)90184-5.
The role of serotonin (5-HT) in analgesia induced by clonidine was examined by determining the effect of intraspinal (i.s.) and intracerebroventricular (i.c.v.) injections of 5,7-dihydroxytryptamine (5,7-DHT) on analgesia produced by clonidine in the tail-flick and hot plate tests. Depletion of amines was verified by high performance liquid chromatography analysis. Intraspinal injections of 5,7-DHT potentiated the action of clonidine in both tests for analgesia and caused depletion of 5-HT in the spinal cord. Intracerebroventricularly injected 5,7-DHT also increased the action of clonidine and depleted 5-HT in brain as well as in the spinal cord. In the groups given intracerebroventricular injections, there appeared to be a biphasic increase in the action of the clonidine. Significant hyperalgesia from pretreatment with neurotoxin was observed only on a limited number of occasions. The present results indicate that 5-HT mechanisms in the CNS are important mediators of the analgesic action of clonidine. Interactions between clonidine and 5-HT systems at both spinal and supraspinal sites are considered.
通过在甩尾试验和热板试验中，测定脊髓内（i.s.）和脑室内（i.c.v.）注射5,7 - 二羟基色胺（5,7 - DHT）对可乐定产生的镇痛作用的影响，来研究5 - 羟色胺（5 - HT）在可乐定诱导的镇痛中的作用。通过高效液相色谱分析验证胺类物质的耗竭情况。脊髓内注射5,7 - DHT在两种镇痛试验中均增强了可乐定的作用，并导致脊髓内5 - HT的耗竭。脑室内注射5,7 - DHT也增强了可乐定的作用，并使脑和脊髓中的5 - HT均耗竭。在接受脑室内注射的组中，可乐定的作用似乎呈双相增加。仅在有限的情况下观察到神经毒素预处理引起的明显痛觉过敏。目前的结果表明，中枢神经系统中的5 - HT机制是可乐定镇痛作用的重要介质。同时考虑了可乐定与5 - HT系统在脊髓和脊髓上部位的相互作用。
