Stroke, Vol 12, 218-293, Copyright © 1981 by American Heart Association
JR Little, A Cook, SA Cook and WJ MacIntyre
The objectives were to study plasma and erythrocyte flow in an area of
acute focal cerebral ischemia and define their relationship to developing
microcirculatory obstruction as determined by morphological techniques.
Eighteen adult cats, anesthetized with ketamine hydrochloride, had right
middle cerebral artery (MCA) occlusion. Plasma flow was determined by
measuring the transit of Iodine-131 (131I) albumin and erythrocyte flow was
determined by measuring the transit of Technetium-99 (99Tc) labeled
erythrocytes in the right Sylvian region. Transit studies were performed
before and immediately after right MCA occlusion and at the end of the
ischemic period, 1 hour, 3 hours, or 6 hours after occlusion.
Intra-arterial perfusion with a buffered formaldehyde - colloidal carbon
solution was carried out after completion of the isotope studies. Swelling
of cerebral tissue and impaired carbon filling in the right MCA territory
were seen initially after 3 hours occlusion and were more severe after 6
hours occlusion. Ischemic neuronal alterations, edema formation, and
capillary luminal narrowing increased with longer periods of occlusion.
131I albumin transit time in the right Sylvian region was 8 +/- 2 seconds
before occlusion and 10 +/- 2 seconds immediately after occlusion. 99Tc
erythrocyte transit time was 10 +/- 2 seconds before occlusion and 12 +/- 3
seconds immediately after occlusion. 99Tc erythrocyte transit time was 10
+/- 2 seconds before occlusion and 12 +/- 3 seconds immediately after
occlusion. Transit times increased progressively with longer periods of
occlusion in cats developing cortical ischemic changes. No evidence of
complete microcirculatory obstruction to albumin and erythrocyte transit
was seen in cats with 6 hours of occlusion despite the impaired filling of
the cortical microcirculation with carbon. There were no findings to
substantiate the hypothesis that plasmapheresis develops during the early
phases of cerebral infarction.
ARTICLES
Microcirculatory obstruction in focal cerebral ischemia: albumin and erythrocyte transit
|
Stroke Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 1981 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |