氯胺酮的镇痛作用及其对大鼠大脑皮层NO/NOS的影响

为了观察大鼠切口疼痛模型中皮下注射氯胺酮对大鼠的镇痛作用,及其对大脑皮层一氧化氮(NO)和一氧化氮合酶(NOS)的影响。采用体重(250±20)g雄性SD大鼠80只,其中行为学评分分生理盐水组,氯氨酮组(5m g/kg组,10m g/kg组、20m g/kg组)和吗啡组共5组,每组8只;NO和NOS测定分正常对照组、生理盐水组、氯胺酮组(10m g/kg组、20m g/kg组)和吗啡组共5组,每组8只。按B rennan法制成切口疼痛模型,以累积疼痛评分和冷刺激评分确定疼痛行为。给药后30m in取大脑皮层,测定NO含量、NOS(总NOS和iNOS)活性。结果表明,氯胺酮组(10m g/kg组、20m g/kg组)、吗啡组累积疼痛评分和冷刺激评分均低于生理盐水组(P<0.05);氯胺酮组(10m g/kg组、20m g/kg组)、吗啡组NO含量及NOS活性均低于生理盐水组(P<0.05)。说明在大鼠切口疼痛模型中,皮下注射不同剂量氯胺酮能产生镇痛作用,NO和NOS可能在氯胺酮的中枢神经系统的镇痛作用中发挥了重要作用。

The Analgesic Effect of Ketamine and its Effect on Nitric Oxide and Nitricoxide Synthase in Cerebral Cortex of Rat

In order to observe the analgesic effect of hypodermic injection of Ketamine in a rat model of incisional pain and the effect on Nitric Oxide(NO) and Nitricoxide synthase(NOS) in the cerebral cortex,eighty male SD rats weighing of(250±20) g were used in our experiment.These animals were equally divided into 10 groups.Among them,5 groups were used in ethology investigation of Saline,Ketamine(5mg/kg,10mg/kg,20mg/kg),Morphia;another 5 groups were used in NO/NOS measurements of normal control,Saline,Ketamine(10mg/kg,20mg/kg) and Morphia.According to the Brennan''s method to build an incision pain model,cumulative pain score and cold stimulation score were utilized to assess pain behavior.The cerebral cortex was removed at 30min after administration to measure NO production and NOS(total NOS and iNOS) activity.Results indicated that the cumulative pain score and cold stimulation score were lower in Ketamine groups(10mg/kg group and 20mg/kg group) and Morphia group than Saline group(P<0.05);and the NO production and the NOS activity in Ketamine groups(10mg/kg and 20mg/kg groups) and Morphia group were lower than Saline group(P<0.05).It produces that the analgesic effect could be produced by hypodermic injection of different dosage Ketamine in a rat model of incisional pain.No and NOS may play an important role in the analgesic effect of the central nervous system.