丹参酮IIA对神经性痛大鼠脊髓背角Bcl-2和Bax表达的影响

Effects of Tanshinone IIA on Expression of Bcl-2 and Bax and in Spinal of Rats with Neuropathic Pain

目的:探讨丹参酮IIA的镇痛机制,研究其对慢性神经病理性痛大鼠脊髓背角内Bcl-2蛋白、Bax蛋白和Caspase-3蛋白表达的影响。方法:45只SD大鼠被分为假手术组和模型组,假手术组仅暴露实验大鼠右侧坐骨神经干不予结扎,模型组结扎实验大鼠右侧坐骨神经干,生理盐水组是在模型组大鼠鞘内注射生理盐水,处理组是在模型组大鼠鞘内注射丹参酮IIA,检测各组大鼠机械痛阈和热痛阈,采用免疫荧光组织化学检测各组大鼠脊髓背角内Bcl-2蛋白、Caspase-3蛋白和Bax蛋白的表达。结果:假手术组大鼠的热痛阈和机械痛阈较高,脊髓背角内仅有少量的Bcl-2蛋白、Bax蛋白和Caspase-3蛋白表达;与之比较生理盐水组大鼠的热痛阈和机械痛阈降低,Bcl-2蛋白、Bax蛋白和Caspase-3蛋白的表达增多,Bcl-2/Bax比值减小,说明大鼠模型制备成功可以进行后续实验;与生理盐水组比较,处理组脊髓背角内Bcl-2蛋白的表达增多,但Bax蛋白和Caspase-3蛋白的表达下降,Bcl-2/Bax比值增大,处理组热痛阈和机械痛阈升高。结论:该研究中丹参酮IIA的镇痛作用可能与脊髓背角内Bcl-2蛋白和Caspase-3蛋白的增多以及Bax蛋白的降低有关。

Objective:To observe effects of Tanshinone IIA on expression of Bcl-2、Bax and Caspase-3 in spinal dorsal horn of rats with neuropathic pain,and to explore analgesic mechanism of tanshinone IIA.Methods:Sham group and chronic constriction injury of the sciatic nerve(CCI)group were randomly divided.The right sciatic nerve of rats were exposed in sham group,and the right sciatic nerve of the rats of CCI group were ligated.CCI group was divided into saline group and treatment group(TSA group).Nature saline and tanshinone IIA were intrathecally injected respectively in the CCI group.Mechanical nociceptive thresholds were assessed by paw withdrawal thresholds(PWTs)with von Frey filament and the paw withdrawal thermal latency(PWTL)was examinated.Bcl-2、Bax and Caspase-3 of the spinal dorsal horn were measured with immunofluorescent histochemistry method.Results:The PWTs and PWTL increased,and only a small amount of Bcl-2、Bax and Caspase-3 were expressed in the sham group.Compared with the sham group,the PWTs and PWTL decreased,the expression of Bcl-2、Bax and Caspase-3 increased significantly,and the ratio of Bcl-2/Bax decreased in the saline group.Compared with the saline group,the PWTs and PWTL increased,and the expression of Bax and Caspase-3 reduced significantly,but the expression of Bcl-2 increased significantly,the ratio of Bcl-2/Bax increased in the TSA group.Conclusions:Intrathecal injection of tanshinone IIA can exert analgesic effect on neuropathic pain of rats by promoting the expression of Bcl-2 and inhibiting the expression of Bax and Caspase-3 in the spinal dorsal horn.