大鼠鞘内促肾上腺素皮质激素释放激素抗伤害性效应的实验研究

Antinociceptive efficacy of preemptive intrathecal administration of CRH in rats

目的探讨鞘内预注促肾上腺素皮质激素释放激素(corticotropinreleasinghormone,CRH)是否对甲醛疼痛模型具有抗伤害性效应。方法采用疼痛行为学观察和辐射热测痛评价CRH对甲醛疼痛模型的镇痛作用,采用免疫组化技术结合计算机图像处理系统观察对脊髓后角c- fos基因表达的影响。结果与NS对照组比较,鞘内预注CRH0.5μg可明显降低甲醛致痛大鼠的Ⅱ相疼痛反应时间,同时可以抑制脊髓后角浅层c -fos基因表达增强的效应,提前1h腹腔内注射CP154526可抵消这种抑制效应。结论鞘内预注CRH能明显抑制甲醛致痛大鼠的痛反应和脊髓后角的c- fos基因的表达,具有抗伤害性效应。

Objective To investigate whether preemptive intrathecal administration of CRH has an antinociceptive efficacy on inflammatory pain model rats, Methods The antinociceptive efficacy of preemptive intrathecal administration of CRH was evaluated by the flinch-licking time and the tail flicking latency in formalinsubjected pain model rats. The c-fos gene expression in spinal cord dorsal horn was analyzed by immunohistochemical technique and computer image technique. Results Comparing with NS control group, preemptive intrathecal administration of 0. 5 Ixg CRH could markedly inhibit the phase Ⅱ pain reaction and meanwhile decrease c-fos gene expression by 25.02% in the superficial lamella of spinal cord dorsal horn of the model rats. The antinociceptive efficacy could be counteracted by preemptive intraperitoneal injection of CP-154526 （the specific antibody of CRHR1, 10 mg/kg）. Gonelusion CRH could significantly inhibit pain reaction and spinal cord c-fos gene expression, and thereby preemptive intratheeal administration of CRH will contribute to the antinociceptive efficacy because of its potency of inhibiting hyperalgesia.