Study Of Amlodipine On Brain Edema And AQP4 Expression In Spontaneously Hypertensive Rats With Acute Intracerebral Hemorrhage

Objective To explore the potential mechanism of amlodipine on brain edema and aquaporin4(AQP4) expression following intracerebral hemorrhage in spontaneously hypertensive rats(SHRs).Methods A model of intracerebral hemorrhage was induced by infusion of bacterial collagenase into the SHRs brains.The rats were randomly assigned to intracerebral hemorrhage group(ICH), amlodipine treatment group(CCB,amlodipine 5mg qd) and intensive amlodipine treatment group (iCCB,amlodipine 10mg qd). The rats were decapitated and brain tissue was collected. The histological morphlogical change was investigated by hematoxylin-eosin (HE) staining. Cerebral edema formation was determined by brain water content using dry-wet weight methods. The expression of AQP4 in brain tissue was observed by immunohistochemistry and RT-PCR.Results 1. Amlodipine treatment lowered the blood pressure in SHR rats and reduced cerebral edema, intensive amlodipine treatment group was better than amlodipine treatment group. 2. Brain water content and AQP4 expression were significantly increased in intracerebral hemorrhage group than other groups. 3. Amlodipine treatment significantly decreased brain water content in brain. Futhermore , amlodipine treatment might inhibit AQP4 expression.Conclusion 1. The rat model of intracerebral hemorrhage in SHR rats made by infusion of bacterial collagenase was sucessful. 2. AQP4 might involve in brain edema formation following intracerebral hemorrhage. 3. Amlodipine treatment has a positive effect by ameliorating cerebral edema formation significantly. 4. It is assumed that the inhibition of AQP4 expression to relieve cerebral edema may be one of the mechanisms of treatment by amlodipine.