Induced hypertension treatment to improve cerebral ischemic injury after transient forebrain ischemia

The effect of induced hypertension treatment on cerebral ischemia is still controversial. We investigated the preferred blood pressure manipulation le vel and presser agent required to reduce cerebral ischemic injury following transient forebrain ischemia induced by bilateral occlusion of the common carotid arteries in anesthetized gerbils. Following 60-min cerebral ischemi a, we evaluated the preferred blood pressure manipulation level and presser agent required to treat cerebral ischemic injury after reperfusion by exam ining the effects of different levels of mean arterial blood pressure (MABP ), increased with phenylephrine or angiotensin Ii or decreased by blood wit hdrawal, on cerebral blood flow (CBF), survival ratio, cerebral edema, and brain energy metabolism following transient forebrain ischemia in gerbils. Mild phenylephrine-induced hypertension treatment (21 +/- 4 mmHg) during po st-cerebral ischemia-reperfusion improved the survival ratio and reduced ce rebral edema, which was also associated with an increase in local CBF and a recovery of brain energy metabolism. However, intense phenylephrine-induce d hypertension, angiotensin II-induced hypertension, or hypotension worsen the survival rate and produced extra cerebral edema, that were also associa ted with deterioration of brain energy metabolism. These results demonstrat e that a mild induced hypertension with phenylephrine (21 +/- 4 mmHg above the baseline level) results in reduction of the cerebral edema and improves the survival ratio and brain energy metabolism, Furthermore, angiotensin I I may have neurotoxic effect to use as the presser agent for induced hypert ension after cerebral ischemia. (C) 1999 Elsevier Science B.V. All rights r eserved.