The Expression Of Aquaporin 4 In Rat Brain Tissue After Subarachnoid Hemorrhage And The Effect Of Dexamethasone, Hyperbaric Oxygen On It

【Objective】To investigate the expression of aquaporin 4(AQP4) in rat brain tissue after subarachnoid hemorrhage(SAH) and the relation between brain edema and AQP4 expression; to discuss the protective effect of treatment with dexamethasone and hyperbaric oxygen for SAH.【Methods】120 healthy adult Wistar rats were randomly divided into control group(n=6), sham operation group(n=6), SAH group(n=36), DEX group(n=36) and HBO group(n=36). Subarachnoid hemorrhage model was induced by injection of the autologous blood into the cisterna magna twice. Neurobehavior scale was applied to observe normal conditions of rats, Western-blot method was used to determine the expression of aquaporin 4 protein.【Results】The expression of AQP4 and brain water content of SAH group were obviously higher than those in normal control group and sham operation group,showing significant difference (P＜0.05). AQP4 protein on the 2ndd after SAH had no obvious difference compared with it on the 3ndd after SAH (P＞0.05), then the expression of AQP4 and brain water content increased at different postoperative intervals after SAH and reached peak on D7 following SAH. The expression of AQP4 was positively correlated with brain water content (P＜0.05). There was obvious difference compared DEX2d group with SAH2d group (P＜0.05), and other DEX group had no obvious difference compared with related SAH each group in the expression of AQP4 and brain water content. The expression of AQP4 in HBO group was lower than that in SAH group at each postoperative intervals (P＜0.05).【Conclusion】The brain tissue has edema in the rats of SAH, had same change curve with the expression of AQP4. Giving dexamethasone can not decrease the expression of AQP4, but HBO therapy can effectively decrease AQP4 expression, thus alleviate cerebral edema.