布托啡诺对大鼠脊髓阿片受体表达的影响

Effects of butorphanol on expression of opiate receptors in spinal cord of rats

目的评估大鼠鞘内注射不同剂量布托啡诺镇痛效果及其对脊髓阿片受体基因表达的影响。方法112只雄性SD大鼠随机分成7组。C_0组不做任何处理,V组与C_1组分别经尾静脉注入布托啡诺0.2 mg/kg及等容生理盐水,T_1、T_2、T_3、C_2组鞘内注射布托啡诺10、20、30μg及生理盐水。记录注射前后热甩尾潜伏期(TFL)变化。注射后1 h、2 h各组取8只大鼠的L_(3～5)脊髓,以RT-PCR技术检测κ、δ、μmRNA的表达水平。结果T_2、T_3、V组注药后1 h、2 h镇痛效果相仿且优于T_1组。V、T_1、T_2、T_3组1、2 h时κ受体表达升高,而μ受体与δ受体表达下降,并以2 h为著,并且组间差异有统计学意义(P<0.05,或P<0.01)。结论鞘内注射布托啡诺20μg与30μg对热甩尾潜伏期镇痛效果相仿。大鼠鞘内注射布托啡诺可促进大鼠脊髓κ受体及抑制μ受体与δ受体的表达,并且上述效应呈剂量依赖性。

Objective To investigate the effects of intrathecal butophanol in different dose on expression of opiate receptors in spinal cord of rats. Methods 1 12 male SD rats were divided into 7 groups randomly. There was no injection in group CO ; groups V and C1 were administered butophanol 0.2 mg/kg and saline through vena caudalis respectively, groups T1 ,T2, T3 and C2 were administered butophanol 10, 20, 30 μg and saline（ 20 μl）through intrathecal tract respectively. Rat tail -flick latency（TFL） time in each group was recorded. Eight animals were sacrificed and the lumbar segment（ L3-5 ） of the spinal cord was obtained for determination of the gene expression of κ, δ and μ opiate receptors in each group at 1 h and 2 h after injection. Results The analgesic effects in group T2 , T3 and V were the same and better than that in group T1 1 h and 2h after injection, and there was no statistically significant different in TFL among three groups. The κ -opiate receptor expression in the spinal cord was higher in group V ,T1 ,T2 , and T3 than those in control groups at 1 h and 2 h. Both δ and μ opiate receptor expressions in the spinal cord were significantly lower in group V,T1 ,T2, and T3 than in control groups at 1 h and 2 h, and there were difference among groups （ P 〈 0. 05 or P 〈 0. 01 ）. Conclusion Intrathecal butophanol promotes the expression of κ opiate receptor and suppresses δ and μopiate receptors in the spinal cord in dose dependent manner. And iutrathecal butophanol 20 or 30 μg produces the same analgesic effect on rat tail -flick latency time.