吗啡依赖和戒断大鼠中枢cAMP和cGMP含量的变化

目的　研究吗啡依赖和催促戒断大鼠中枢cAMP和cGMP含量变化。方法　以剂量递增法连续皮下注射吗啡建立吗啡依赖模型 ,采用放射免疫学方法检测脑内cAMP和cGMP含量。结果　与生理盐水对照组大鼠比较 ,吗啡依赖大鼠的纹状体、间脑、中脑、脑桥和海马内cGMP含量均显著降低 ,cAMP含量和cAMP/cGMP比值显著升高 ,而小脑则无类似变化 ;与吗啡依赖组大鼠比较 ,纳洛酮催促戒断大鼠 ,其海马和纹状体内的cGMP含量显著下降 ,cAMP含量和cAMP/cGMP比值显著升高 ;其它部位无明显变化。结论　中枢cAMP和cGMP含量变化 ,可能是形成和维持吗啡依赖和戒断的重要分子机制之一。

Changes of cAMP and cGMP contents in the central nervous system in morphine dependent and withdrawal rats

Objective To investigate the contents of cAMP and cGMP in the central nervous system in morphine dependent and withdrawal rats.Methods A physical morphine dependent model in rats was established by subcutaneous injection of morphine in gradually increasing doses.The cAMP and cGMP contents in the brain regions were determined by radioimmunoassay.Results Compared with control group,morphine dependence could significantly decrease the cGMP content or profoundly increase the cAMP content and the cAMP/cGMP ratio in rat striatum,diencephalons,midbrain,pons and hippocampus,but these changes described above were not detected in cerebellum.Compared with morphine dependent group,naloxone induced withdrawal could significantly decrease the cGMP contents or increase the cAMP contents and the cAMP/cGMP ratio in striatum and hippocampus,but these changes described above were not observed in the other regions.Conclusion The changes of the cAMP and cGMP contents may be one of the important molecular mechanisms leading to morphine dependence and abstinence.