替来他明对大鼠不同脑区NO-cGMP信号转导系统的影响

Effect of tiletamine on the NO-cGMP signal transduction in different brain regions of rats in vivo

SD大鼠80只,随机均分为两组,一组测定脑NOS活性、NO产量,另一组测定脑cGMP含量。每组又随机均分为对照组、麻醉组、恢复Ⅰ组和恢复Ⅱ组等4个亚组。用分光光度法测定脑NOS活性和NO产量,用放射免疫法测定脑cGMP含量。结果显示,在麻醉组不但大脑皮层、海马和丘脑的NOS活性受到明显抑制,而且显著(P<0.05)减少上述脑区NO产量和cGMP含量。在恢复Ⅰ组上述脑区NOS活性、NO产量、cGMP含量大体呈恢复趋势,在恢复Ⅱ组呈现明显恢复。在替来他明麻醉过程中脑干、小脑的NOS活性、NO产量和cGMP含量未发生明显的变化。结果表明,替来他明麻醉作用可能与抑制大脑皮层、丘脑和海马等脑区NO-cGMP信号转导系统相关。

Eighty SD rats were divided randomly into two groups. One was used to measure brain NOS activity and NO production,and the other was used to measure cGMP content. Each group was divided ran- domly into four subgroups of control group, anesthesia group, recovery group Ⅰ, and recovery group Ⅱ. The NOS activity and NO production were examined by spectrophotometric analysis, and the cGMP content was examined by radioimmunoassay（RIA）. The activities of NOS in cerebral cortex, hippocampus and thalamus in the anesthesia group was inhibited obviously,and the NO production and cGMP content in the abovementioned regions decreased obviously compared with that of the control group（P〈0.05）. The NOS acti- vity, NO production, and cGMP content in the cerebral cortex, hippoeampus, and thalamus were effected by tiletamine in the recovery group Ⅰ. Though the degree was not consistent, the tendency presented recovery in general. In the recovery group Ⅱ,the NOS activity, NO production,and cGMP content in the cerebral cortex,hippocampus,and thalamus revived obviously compared with that of the control group（P〈0.05）. The NOS activity, NO production, and cGMP content in the brain stem and cerebellum were not significantly changed in the process of general anesthesia of tiletamine. It was concluded that the anesthesia effects of tiletamine may relate to inhibition of NO-cGMP signal transduction in the cerebral cortex,thalamus, and hippoeampus.