8溴-环磷酸腺苷对脑缺血再灌注大鼠PKA及GAP-43蛋白表达的影响

目的:观察脑室注射8-溴-环磷酸腺苷(8-B-cAMP)对脑缺血再灌注大鼠大脑皮质蛋白激酶A(PKA)及生长相关蛋白43(GAP-43)表达的影响。方法:采用线栓法制作大鼠脑缺血再灌注模型,将45只大鼠分为假手术对照组,缺血组(单纯脑缺血再灌注组)和8-B-cAMP组(脑缺血再灌注并脑室注射8-B-AMP)。用放免法测缺血周边区脑组织cAMP的含量,Westernblot(免疫印迹法)检测蛋白激酶A(PKA)及生长相关蛋白43(GAP-43)的表达。结果:脑缺血组6h、24h cAMP的含量下降,GAP-43及PKA蛋白表达减少;8-B-cAMP治疗组脑组织GAP-43蛋白表达较缺血组增加,且这种变化与cAMP的含量及PKA蛋白表达增加相一致。结论:8-B-AMP能够增加PKA及GAP-43的表达从而促进脑缺血再灌注后的轴突再生。

The expression of Growth associated protein-43 and protein kinase A increased by intra-cerebroventricular administration of 8-B-cAMP in rats with focal cerebral ischemia and reperfusion

Objective: To investigate the effect of 8-B-cAMP on The expression of protein kinase A(PKA) and Growth associated protein-43 (GAP-43). Methods: The focal cerebral ischemia and reperfusion model was induced by nylon monofilamem in rats. Forty five rats were randomly assigned to sham operated (control)group, cerebral ischemia- reperfusion only group and 8-B-cAMP group (intra-cerebroventricular inject 8-B-cAMP). The contents of cAMP in cerebral cortex of rats was detected by radio immunoassay (RIA) and the change of PKA and GAP-43 protein expression was determined by Western blot technique. Results: The contents of cAMP and the expression level of PKA and GAP-43 protein decreased at 6h and 24h after cerebral ischemia- reperfusion. 8-B-cAMP elevated the expression level of GAP-43 protein and increased the contents of cAMP and activated PKA. There is a coincidence between the change of GAP-43 and cAMP-PKA. Conclusion: 8-B-cAMP can increase the expression level of GAP-43 and PKA protein and improve axon regeneration.