The effect of induced hypertension on neurological outcome in forebrain ischaemia model in rats.

Abstract

The present study investigated the effects of induced hypertension on hippocampal cell death after forebrain ischaemia in rats. In this study, forebrain ischaemia was induced in 20 Sprague-Dawley rats by clamping the bilateral common carotid arteries to induce systemic hypotension for 8min. All rats then underwent reperfusion during which the induced hypertension group (n=10) received intermittent intravenous injections of phenylephrine (5μg) to maintain their mean arterial blood pressure at 20mmHg above baseline for 10min and the control group (n=10) did not receive any treatment. In both groups, the numbers of viable and apoptotic neuronal cells in the cornu ammonis 1 (CA1) area of the hippocampus were evaluated 7 days after the induction of ischaemia. The mean percentage of viable neuronal cells was higher in the induced hypertension group than in the control group (35% vs. 26%, respectively; p=0.004), but there was no significant difference in the proportion of apoptotic neuronal cells between the groups (57% vs. 43%, respectively; p=0.165). Induced hypertension significantly attenuated necrotic cell death in the hippocampal CA1 area, but apoptotic cell death was not affected.