THE EFFECT OF AQUAPORIN-4 ON BRAIN EDEMA FOLLOWING SUBARACHNOID HEMORRHAGE IN RATS

Objective To study the relationship between the expression of aquaporin-4(AQP-4) and cerebral edema formation during the pathologic process following subarachnoid hemorrhage(SAH) in rats. Methods The SAH model was established by injecting autologous blood into the cisterna magna.The changes of brain water content were measured by the wet and dry weight methods.Immunohistochemistry was used to determine the changes of the expression of aquaporin-4 in cerebral cortex and thalamus on different times. Results The expression of AQP-4 in the edematous tissue increased at 8 hours following SAH.At 48 h,the expression of AQP-4 reached its maximum,and the brain edema became remarkable.On 7th day,the expression of AQP-4 in SAH group was still higher than that in the control group and the brain edema was unremarkable. Conclusion The expression of AQP-4 increases remarkably after SAH and shows positive correlation with cerebral edema,which suggests that AQP-4 play an important role in process in cerebral-edema formation following SAH.