Down The Water Channel Protein -4 Reduce Ischemic Brain Edema And Gender Relations

Background and Purpose:Aquaporin-4(AQP4) has been shown to be important in the evolution of stroke associated cerebral edema. However the role of AQP-4 in cerebral edema as it pertains to sex has not been previously studied. The perivascular pool of AQP4 is important in the influx and efflux of water during focal cerebral ischemia. The present study was designed to address whether there is a difference in evolution of edema after experimental stroke in adult male and randomly cycling female animals and if AQP4 is involved in this process.Methods:Mice with targeted disruption of the gene encodingα-syntrophin(α-Syn-/-)that lack the perivascular AQP4 pool but retain the endothelial pool of this protein were subjected to 90 mins middle cerebral artery occlusion (MCAO), and infarct volume was measured at 72 hours of reperfusion by TTC staining and compared to wild-type mice. Cerebral hemispheric edema was assessed by comparing wet-to-dry ratios (WDR) and AQP4 protein expression was analyzed by Western blot at 48 hours of reperfusion after MCAO. Regional CBF was measures at the end of MCAO using iodoantipyrine (IAP) autoradiography.Results:Infarct volume at 72hours after transient focal ischemia ( 90 mins) in isoflurane–anesthetized mice was attenuated in both sexes withα-Syn deletion as compared with their wild-type ( WT ) counterparts. There was no sex differences in hemispheric water content in WT andα-Syn deletion mice or regional AQP4 expression in WT mice. In neither sex didα-Syn deletion lead to alterations in end-ischemic regional cerebral blood flow ( rCBF )。Conclusion:(1) There is no significant differences in stroke associated cerebral edema based on sex; (2) The perivascular domain of AQP4 shown to be critical in water influx and efflux does not play a significant role in sex based differences in ischemic brain injury;(3) Neuroprotection observed withα-Syn deletion is not related to modulation of end-ischemic rCBF。...