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

Introduction: The present study investigated the effects of induced hypertension on hippocampal cell death after forebrain ischaemia in rats.

Materials And Methods: 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.

Results: 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).

Conclusions: Induced hypertension significantly attenuated necrotic cell death in the hippocampal CA1 area, but apoptotic cell death was not affected.