补阳还五汤对血管性痴呆大鼠海马cAMP-PKA-CREB信号通路的影响

摘要

目的:观察补阳还五汤对血管性痴呆大鼠海马组织环磷酸腺苷(cAMP)-蛋白激酶A(PKA)-cREB反应元件结合蛋白(CREB)信号通路的影响.方法:将大鼠随机分为补阳还五汤组、尼莫地平组、模型组、假手术组.用改良Pulsinelli's四血管阻断法建立血管性痴呆大鼠模型,分别给予相应的药物,连续30 d.利用放射免疫分析法检测海马组织cAMP含量,Western blotting法检测PKA催化亚基(PKAc)蛋白表达,电泳迁移率改变分析法检测CREB的DNA结合活性.结果:与假手术组比较,模型组大鼠海马组织cAMP含量、PKAc蛋白表达和CREB的DNA结合活性均降低(P<0.01);与模型组比较,补阳还五汤组和尼莫地平组cAMP含量、PKAc蛋白表达和CREB的DNA结合活性均升高(P<0.01).结论:补阳还五汤可增加血管性痴呆大鼠海马cAMP含量、PKAc蛋白表达和CREB的DNA结合活性,增强cAMP-PKA-CREB信号通路的作用.%AIM: To evaluate the role of concentrated decoction of Chinese herbal compound Buyanghuanwutang ( BYHWT ) in cyclic adenosine monophosphate( cAMP ) - protein kinase A( PKA ) - cAMP response element - binding protein( CREB ) signaling pathway in hippocampus of rats with vascular dementia ( VD ).METHODS: The rats were randomly divided into sham operation group ( sham - operated rats treated with normal saline ), VD model group ( VD rats treated with normal saline ), BYHWT treatment group ( VD rats treated with BYHWT ) and nimodipment treating group ( VD rats treated with nimodipine ).The rat model of VD was build by the method of four - vessel occlusion.The rats in all 4 groups were administered with the corresponding reagents for successive 30 days.The content of cAMP was measured by radioimmunoassay.The expression of PKA catalytic subunit ( PKAc ) was observed by Western blotting.The changes of DNA - binding activity of CREB in rat hippocampus were detected by electrophoretic mobility shift assay.RESULTS: The content of cAMP, the expression of PKAc and the DNA - bingding activity of CREB in the hippocampus of VD rats were lower than those in the hippocampus of sham - operated rats ( P ＜0.01 ).The above indexes in both nimodipine treatment group and BYHWT treatment group were definitely higher than those in VD model group ( P ＜0.01 ).CONCLUSION: BYHWT increases the content of cAMP, the expression of PKAc and the DNA - binding activity of CREB in VD rat hippocampus , thus strengthening the cAMP - PKA - CREB signaling pathway.