Changes of NCCa-ATP Channels in Core Area During Focal Cerebral Ischemia and Reperfusion in Rats / 昆明医科大学学报

ABSTRACT

Objective To study the changes of SUR1-regulated NCCa-ATP channels in core area during focal cerebral ischemia and reperfusion in rats, and to explore the therapeutic window of focal cerebral ischemia. Methods Adult male Wistar rats were rendered to undergo 120 minutes of the left middle cerebral artery occlusion (MCAO) by the intraluminal thread technique before reperfusion. The core area of the left hemisphere cortex ischemia/reperfusion at different times (reperfusionR3 h, 6 h, 8 h, 12 h and 24 h) was taken to be tested the level of mRNA and protein expression of sulfonylurea receptor 1 (SUR1) using RT-PCR and Western-blot techniques. SUR1 of the ischemic brain microvascular endothelial cells were observed by immunofluorescence double staining at the peak expressing time point of SUR1. Results We found the up-regulation of SUR1 mRNA and SUR1 protein in ischemic infarcts tissues for R3 h, 6 h, 8 h and 12 h, peaked at R8 h, compared with the sham-operation group ( <0.05) . However, SUR1 expression increased was observed at R12 h by double immunofluorescence in microvascular endothelium. Conclusion SUR1-regulated NCCa-ATP channel may take part in cerebral ischemic damage during focal cerebral ischemia and reperfusion. The expressions of SUR1 mRNA and SUR1 protein were up-regulated in ischemic infarcts tissues. The data suggested that the best time to apply SUR1 inhibitor is within 8-12 hours after ischemia and reperfusion.