大鼠触液核中TRPC6的分布及其在吗啡依赖与戒断条件下的表达

Distribution of TRPC6 in the cerebrospinal fluid-contacting nucleus of rat and its expression in the model of morphine dependence and withdrawal

目的:研究TRPC6在大鼠触液核(cerebrospinal fluid-contacting nucleus,CSF-CN)中的分布及其在吗啡依赖与戒断条件下的表达变化。方法:雄性SD大鼠随机分为4组:正常大鼠组、生理盐水组、吗啡依赖组和吗啡戒断组。每组大鼠进行戒断总评分(total withdrawal scores,TWS);采用侧脑室注射CB-HRP,并结合CB-HRPP/TRPC6免疫荧光双标技术,观察大鼠触液核内TRPC6的表达情况。结果:上述4组大鼠的戒断总评分分别为2.0±0.6、2.1±0.7、2.6±0.7和41.0±4.6,其中吗啡戒断组与其他三组相比,差异具有显著性(P<0.01);在侧脑室注射CB-HRP后,上述4组大鼠触液核内可观察到大量的CB-HRP标记神经元;同时在触液核内也可观察到部分神经元表达TRPC6免疫阳性。经计数,CB-HRP/TRPC6双标神经元的数量分别为81.78±4.93、79.44±7.09、254.61±15.36和260.00±12.04,其中吗啡依赖组和吗啡戒断组分别与其他两组相比,差异具有显著性(P<0.01);但吗啡依赖组和吗啡戒断组相比,差异无显著性(P>0.05)。结论:正常大鼠触液核内表达TRPC6;触液核可能通过上调TRPC6的表达参与吗啡依赖和戒断的形成。

Objective： To investigate the role of cerebrospinal fluid contacting nucleus （CSF-CN） of rat and the changes of TRPC6 expression in morphine dependence and withdrawal. Methods： Male Sprague-Dawley rats were randomly divid- ed into four groups： the normal group; the saline group; the morphine dependence group and the morphine withdrawal group. All animals in each group were tested the morphine withdrawal-like behavioral signs by total withdrawal scores （TWS）. The expression of TRPC6 in CSF-CN in rats was observed by CB-HRP injection into lateral ventricle combined the double-labeled immunofluorescent technique （CB-HRPP/TRPC6）. Results ： TWS of the four groups were 2.0 ± 0.6, 2.1 ± 0.7, 2.6 ± 0.7 and 41.0 ± 4.6, the difference was significant in the morphine withdrawal group compared with other groups（ P 〈0.01 ）. A large number of CB-HRP labeled neurons were found in all groups after CB-HRP injectioninto lateral ventricle. Some neurons of CSF-CN was observed to be TRPC-6-positive. The numbers of CB-HRP/TRPC6 double labeled neurons in the four groups were 81.78 ±.93, 79.44 ±09,254.61 ±15.36,260.00 ± 12.04, respec- tively. The difference was significant when the morphine dependence group and morphine withdrawal group compared with the normal group and saline group （ P 〈 0.01 ）. But there was no significant between the morphine dependence group and the morphine withdrawal group （ P 〉 0.05 ）. Conclusion： TRPC6 was expressed in CSF-CN of the normal rats. CSF-CN might participate in the development of morphine dependence and withdrawal by the up-regulated expression of TRPC6.