The Effect And Significance Of Inosine On Expression Of COX-2, CaN And VEGF Following Cerebral Ischemic Reperfusion In Rats

Objective: From the changes of the expression of cyclooxygenase-2 (COX-2), calcineurin (CaN) and vascular endothelial growth factor (VEGF) to observe the possible protective mechamism of Inosine on the ischemic cerebral tissue, and to explore if the protective effect of Inosine is relevant to the expression of COX-2, CaN and VEGFafter reperfusion of MCAO in rats.Methods: The models of middle cerebral artery occlusion (MCAO) reperfusion were established with SD rats, which were divided into the controlled group (saline solution was injected intraperisoneally) and the Inosine group (Inosine was injected intraperisoneally). Each group was divided into eight subgroups at reperfusion 2h, 6h, 12h, 24h, 2d, 3d, 7d, 14d which consisted of 4 rats. In situ hybridization and immunohistochemical techniques were used to investigate the dynamic changes of COX-2, CaN and VEGF in cerebral tissue.Results: â‘  COX-2 mRNA: The expression of COX-2 mRNA occurred at 6h, peaked a: 12h, maintained 24h-48h after reperfusion and decreased gradually to the lowest level at 14d. The level of COX-2 mRNA in cerebral cortex was higher than that in striatum. Compared with the controlled group, the use of Inosine could elevate the level of COX-2. There was significant difference between the two groups (P<0.01). â‘¡ COX-2: The change of the expression of COX-2 is similar to that of COX-2 mRNA, but the peak occurred at 24h after reperfusion and decreased rapidly. Up to the reperfusion 7d, it dropped to the baseline in brain tissue. The expression of COX-2 in cerebral cortex was higher than that in striatum. Compared with the controlled group, injecting Inosine could elevate the level of COX-2. There was significant difference between the two groups (P<0.01). â‘¢ CaN: The expression of CaN increased temporarily at 6h, 12h and 24h, then decreased immediately after MCAO. At 7d, it dropped to the baseline in cerebral cortex and striatum. The level of CaN in Inosine group was lower than that in the controlled group (P<0.01). â‘£ The expression of VEGF occurred at 2h, the peak at 12h~24h after reperfusion and then...