Stroke, Vol 13, 171-174, Copyright © 1982 by American Heart Association
MM Keykhah, FA Welsh, M Hagerdal and JR Harp
The effect of arterial hypotension on cerebral cortical tissue levels of
adenosine triphosphate (ATP), phosphocreatine (PGr), lactate, and reduced
nicotinamide adenine dinucleotide (NADH) was studied in male Wistar rats
with unilateral carotid ligation exposed to arterial by hypoxia (PaO2 25
torr) for 20 min. while the body temperature was maintained at 32 degrees C
and 27 degrees C. Brain metabolite levels were normal in normotensive
hypothermic animals exposed to hypoxia, but reduction in arterial pressure
to 75 torr caused a significant (p less than 0.05) decrease in ATP and PCr
values and a significant increase in lactate and NADH levels. These changes
were comparable to those of normothermic normotensive, hypoxic animals.
Furthermore, there was no significant differences in the brain metabolite
levels between the two hypotensive hypoxic groups. These results indicate
that arterial hypotension severely alters the cerebral protective effect of
hypothermia against injury caused by hypoxia, and that further reduction in
body temperature (from 32 degrees C to 27 degrees C) will not prevent the
harmful effect of hypoxia upon the brain in hypotensive rats.
ARTICLES
Reduction of the cerebral protective effect of hypothermia by oligemic hypotension during hypoxia in the rat
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