鞘内注射NOS抑制剂对吗啡戒断大鼠脊髓神经元磷酸化CREB表达的影响

Effects of intrathecal injection of NOS inhibitor on the expression of phospho-CREB in spinal cord of morphine-induced withdrawal rats

目的研究鞘内注射NOS抑制剂对吗啡依赖大鼠纳洛酮催促戒断反应、脊髓p-CREB表达的影响。方法建立大鼠吗啡依赖和戒断模型,SD大鼠72只,分为正常对照组、吗啡依赖组、吗啡戒断组、L-NAME组,每组18只大鼠。采用行为学(n=8)、免疫组织化学(n=6)和Western blot(n=4)方法观察鞘内注射L-NAME对吗啡依赖大鼠纳洛酮催促戒断反应、脊髓p-CREB表达的影响。结果 (1)鞘内注射L-NAME、可明显减轻吗啡依赖大鼠戒断症状,戒断组戒断症状评分为28.60±4.89,L-NAME组22.10±4.52(P<0.05);戒断组TEA评分为13.50±2.55,L-NAME组9.80±3.11(P<0.05)。(2)鞘内注射L-NAME可明显减少戒断大鼠脊髓背角p-CREB阳性神经元的数目(380±71),L-NAME组(283±47)低于戒断组(P<0.05)。(3)Western blot结果显示:鞘内注射L-NAME明显抑制吗啡戒断期间脊髓p-CREB表达的增加。结论鞘内注射NOS抑制剂能明显抑制吗啡戒断大鼠脊髓神经元p-CREB的表达。

Objective To explore the effects of intrathecal injection of NOS inhibitor L-NAME on morphine withdrawal response and the spinal phospho-CREB expression in morphine-induced withdrawal rats.Methods Morphine dependence and withdrawal models were developed.72 SD rats were divided into 4 groups： control group,dependence group,withdrawal group,L-NAME group,18 rats for each group.Praxiologic assay（n=8）,immunohistochemical method（n=6） and Western-blotting technique（n=4） were used to evaluate morphine withdrawal response and the expression of phospho-CREB in the spinal cord.Results The results showed that intrathecal injection of NOS inhibitor significantly alleviated morphine withdrawal symptoms.Morphine withdrawal scores in L-NAME group（22.10±4.52）were significantly lower than that of withdrawal group（28.60±4.89）（P0.05）;TEA score of withdrawal group was（13.50±2.55）,which was significantly higher than that of L-NAME group（9.80±3.11,P0.05）.Phospho-CREB positive neurons in the spinal dorsal horn of withdrawal group were 380±71,which was higher that of L-NAME group（283±47,P0.05）.Compared with withdrawal group,level of phospho-CREB protein detected by Western blot in spinal cord of L-NAME group were significantly lower.Conclusion The NOS inhibitor can significantly suppress expression of phospho-CREB in spinal cord.