Facilitation of post-ischemic cerebral reperfusion using [alpha]
-pbn. assessment using nmr and laser doppler flow techniques.
Schulz, J. B., N. Panahian, Y. I. Chen, M. F. Beal, M. A. Moskowitz,
B. R. Rosen, and B. G. Jenkins.
1Neurochemistry Laboratory and Neurology Service, Stroke Laboratory
and Neurosurgery Service, MGH-NMR Center, Massachusetts General
Hospital and Harvard Medical School, Boston, MA 02114
APStracts 3:0517H, 1996.
We examined the effects of the free radical spin trap [alpha]-phenyl
-tert-butyl-nitrone (PBN) on focal cerebral ischemia/reperfusion
injury in halothane anesthetized rats. Ninety minutes after middle
cerebral artery occlusion by an intraluminal filament the artery was
reperfused. Intravenous injections of 25 mg/kg PBN 5 min before and
30 min after insertion of the filament significantly attenuated the
lesion volume measured 24 h after ischemia. During ischemia and
during the first 30 min after reperfusion cerebral blood volume and
blood flow were measured by volume-sensitive and newly developed
flow-sensitive magnetic resonance imaging (MRI) techniques and by
laser-doppler flowmetry. In all animals the area of decreased blood
flow was larger than the area of decreased volume by a factor of 2.2.
The area of the post-reperfusion flow deficits matched the final
lesion volumes at 24 hrs measured histologically much better than did
the blood volume deficits in both saline and PBN-treated animals.
Reperfusion led to a return of blood flow and volume to values close
to the contralateral side in the PBN-treated animals in contrast to
the saline-treated control group. We conclude that in focal
ischemia/reperfusion PBN provides protection of the vascular
endothelium leading to enhanced post-ischemic reperfusion. The
implication of this is that the vascular endothelium may be a primary
target for the damaging action of free radicals given the protection
afforded by putative spin traps.
Received 27 October 1995; accepted in final form 12 November
1996.
APS Manuscript Number H1005-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996