Transvenous perfusion of the brain with verapamil during focal cerebral ischemia in rats.

Abstract

We report on the effect of calcium channel blocker verapamil administered into the inferior cerebral vein in rats 1 hour after occlusion of the middle cerebral artery. Twenty-four rats were divided into four groups of six rats each. Group A rats received no medication. The other three groups received 0.1 mg verapamil/kg/2 hr. Group B rats received verapamil intravenously. Group C and D rats received verapamil and autologous arterial blood by transvenous perfusion of the brain, Group C rats at 100 mm Hg perfusion pressure and Group D rats at 150 mm Hg perfusion pressure. The administration of verapamil started 1 hour after middle cerebral artery occlusion and lasted for 2 hours. Three hours after occlusion, we used double- or single-tracer autoradiography with 4-[18F]fluoroantipyrine or [14C]iodoantipyrine and [14C]alpha-aminoisobutyric acid as tracers to study the brains for local cerebral blood flow and blood-brain barrier permeability changes. Group C showed a significant increase of local cerebral blood flow in the parietal cortex (89%, p less than 0.01) and sensorimotor cortex (64%, p less than 0.05) compared with Group A. Group D showed an extensive and striking increase in local cerebral blood flow of the ischemic cortical and subcortical areas (57-100%, p less than 0.05). Group B showed no significant changes but exhibited further reduction of local cerebral blood flow in the ischemic cerebral hemisphere associated with slightly increased local cerebral blood flow in the nonischemic cerebral hemisphere compared with Group A. There was no change of blood-brain barrier permeability in any group.(ABSTRACT TRUNCATED AT 250 WORDS)