Stroke, Vol 15, 124-129, Copyright © 1984 by American Heart Association
WE Hoffman, RF Albrecht and DJ Miletich
The role of adenosine in the regional cerebral blood flow (rCBF) response
to hypoxia was evaluated in young (6 month) and aged (26-28 month) F344
rats using theophylline, an adenosine antagonist. Regional CBF was measured
with radioactive microspheres under control anesthetized conditions (70%
N2O, 30% O2) and at two levels of hypoxia (CaO2 = 8.7-9.0 ml . 100ml-1 and
3.2-3.7 ml . 100ml-1). Without theophylline infusion, CBF increases were
similar between young and aged rats during moderate hypoxia but were
increased more in young during severe hypoxia. Intracerebrovascular
theophylline infusion significantly attenuated the increase in CBF during
both moderate and severe hypoxia and decreased the difference between young
and aged rats. Theophylline infusion produced no significant effect on the
increase in CBF produced by hypercapnia, indicating the specificity of the
treatment for hypoxic induced CBF changes and adenosine release.
Intracerebrovascular infusion of adenosine had no effect on CBF, presumably
due to the presence of the blood brain barrier. The results suggest that
adenosine plays a major role in CBF increases during both moderate and
severe hypoxia and in the difference in response to hypoxia between young
and aged rats.
ARTICLES
The role of adenosine in CBF increases during hypoxia in young vs aged rats
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