Influence of hypertension on postischemic cerebrovascular obstruction

Rabbit brains were subjected to 15 minutes of complete ischemia, then perfused with carbon black either immediately after the ischemic period, or following 7 1 2 or 15 minutes of reestablished cerebral blood flow at either normotensive or hypertensive blood pressures. The vascular obstruction seen immediately after 15 minutes of ischemia decreased significantly after 7 1 2 or 15 minutes of normotensive-restored blood flow. A further significant decrease was seen when blood flow was reestablished at hypertensive levels as compared with normotensive levels of similar duration. Prolonged reflow (120 minutes) at normotensive levels was no more effective than 15 minutes of hypertensive reflow in reversing vascular obstruction. These findings are discussed in terms of a mechanism for reversing the obstruction, and the possible value of hypertensive therapy in acute episodes of cerebral ischemia is mentioned.