摘要
目的 了解大鼠切口疼痛模型中鞘内（IT）吗啡对脊髓一氧化氮（NO）/环鸟苷酸（cGMP）信号转导系统的影响。方法 雄性SD大鼠64只,随机分为四组,每组16只:假手术组（组I）;术前 30minIT0.9％氯化钠 20μl组（组Ⅱ,对照组）;术后30minIT吗啡5μg组（组 Ⅲ,术后吗啡治疗组）和术前30min IT吗啡5μg组（组Ⅳ,术前吗啡治疗组）。按Brennan法制成切口疼痛模型,以累积疼痛评分确定疼痛行为。在术后2h断头取腰段脊髓,以分光光度法测定NOS活性、NO产量;放射免疫法测定cGMP含量。结果 术后吗啡治疗组和术前吗啡治疗组大鼠的累积评分均明显低于对照组（P<0.01）。在对照组,脊髓的NOS活性、NO产量和cGMP含量均较假手术组明显升高（P<0.01）。术前吗啡治疗组的脊髓NOS活性、NO产量和cGMP含量均较对照组明显降低（P<0.05或0.01）。上述指标两用药组比较以及用药组与假手术组比较均无明显差别。结论 在大鼠切口疼痛模型中,术前IT吗啡的抗伤害作用可能与 NO/cGMP信号转导系统有关。
Objective To evaluate the effects of intrathecal (IT) administration of morphine on nitric oxide/cyclic guanosine 3', 5'- monophosphate (NO/cGMP) signaling pathway of the spinal cord in a rat model of incisional pain. Methods Sixty-four male SD rats weighing 250-300g were anesthetized with pentobarbital sodium 40 mg·kg-1 .A PE-10 catheter was inserted into the lumbar subarachnoid space and a 1 cm incision was made in the plantar area of the left hindpaw, according to the method of Brennan's. The animals were randomly divided into 4 groups of 16 animals each: in group I the animals were sham-operated ; in group Ⅱ normal saline 20μl IT was given 30 min before incision; in groupⅣ morphine 5 μg IT was given 30 min after incision; in group Ⅲ morphine 5μg Ⅱ was given 30 min before incision. A cumulative pain score was utilized to assess pain behavior. The animals were decapitated 2h after incision. The lumbar spinal cord was quickly removed and lumbar enlargement of the spinal cord was dissected on ice. NOS activity and NO production of the spinal cord were measured by spectrophotometry and its cGMP content by radioimmunoassay. Results Cumulative pain score was significantly lower in group Ⅲ and group Ⅳ than that in group Ⅱ (P<0.01). NOS activity, NO production and cGMP content of the spinal cord were significantly increased in groupⅡ as compared with those of sham-operated animals ( P < 0. 01) . In groupⅣ NOS activity, NO production and cGMP content of the spinal cord were significantly lower than those in group Ⅱ , but there was no significant difference in NOS activity, NO production and cGMP content of the spinal cord between groupⅡ and Ⅲ .Conclusion The antinociceptive effect provided by preemptive IT morphine may be associated with the NO/cGMP signaling pathway of the spinal cord in a rat model of incisional pain.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2002年第8期480-482,共3页
Chinese Journal of Anesthesiology
基金
江苏省教委重点实验室开放课题资助(K99036)
关键词
吗啡
疼痛测量
一氧化氮
环GMP
脊髓注射
Morphine
Pain measurement
Nitric oxide
Cyclic GMP
Injections, spinal
