Effect of angiotensin II on cerebral edema following cerebral ischemia and reperfusion

Abstract

Angiotensin II may be a significant contributor to the pathophysiology of ischemic stroke. The major goal of the present study was to clarify the role of angiotensin II in brain ischemia. We investigated the effect of angiotensin II on cerebral ischemic injury following transient forebrain ischemia induced by bilateral occlusion of the common carotid arteries in pentobarbital anesthetized gerbils. Following 60-min cerebral ischemia, we infused angiotensin II ( n=17), phenylephrine ( n=17), or saline ( n=17), and evaluated their effects on blood pressure, cerebral blood flow, survival ratio, cerebral edema, and cerebral energy metabolism. Angiotensin II treatment during post-cerebral ischemic reperfusion worsened specific gravity of cerebral cortex ( p<0.01) in association with a less recovery of brain pHi ( p<0.005). However, phenylephrine treatment, in the same blood pressure manipulation level and duration as angiotensin II treatment, improved the survival rate ( p<0.05) and specific gravity of cerebral cortex ( p<0.005) compared with saline treatment. Therefore, we believe that angiotensin II may have harmful effects in cerebral ischemia.