The AQP9 expression in the early stage of the ischemic brain edema

Objectve The aim of this study was to explore the changes of the aquaporin-9(AQP9)expression in the early stage of the ischemic brain edema.Methods The model of cerebral ischemic of the rats was made by occluding unilateral middle cerebral artery with the suture method.The expression of AQP9 was assessed by morphological changes,immunocytochemistry,in situ hybridization and imaging analysis at interval times of 30 min,1 h,3 h,6 h,24 h after cerebral ischemic,respectively.and compared with control group.Results The expression of AQP9 protein and mRNA increased significantly at 30 min in ischemic edema tissue,there was a significant difference between control group and operation group.At 30 min and 1 h after occlusion,the AQP9 expression of the occluded side of the rat brain in ischemic edema tissue increased rapidly.With the progress of the time(1 h~6 h),the expression of AQP9 increased slowly.Whereas,there was the second peak of the AQP9 expression after 6 h.There was a positive correlation between expressions of AQP9 protein and AQP9mRNA.Meanwhile,microscope showed there were 3 stages of histological changes:intracellular edema,vasogenic brain edema and necrosis of tissue.Conclusions The up-regulated of AQP9 expression might imply that AQP9 would have a close relationship with the formation of brain edema in the early stage after cerebral ischemic.AQP9 may play a key role in intracellular edema of the ischemic brain edema.