AJP - Heart and Circulatory Physiology, Vol 257, Issue 5 1656-H1662, Copyright © 1989 by American Physiological Society
Adenosine and cerebral capillary perfusion and blood flow during middle cerebral artery occlusion
M. Anwar and H. R. Weiss
Department of Physiology Biophysics University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway 08854.
The effects of adenosine on regional cerebral blood flow and indexes of the
total and perfused microvascular bed were studied after 1 h of middle
cerebral artery occlusion in the anesthetized rat. Iodo[14C]antipyrine was
used to determine cerebral blood flow. Fluorescein isothiocyanate-dextran
was used to study the perfused microvasculature, and an alkaline
phosphatase stain was used to identify the total bed. Mean arterial blood
pressure was significantly reduced by adenosine. Cerebral blood flow
increased significantly by 75%, except in the flow-restricted cortex where
flow averaged 28 +/- 15 (SD) ml.min-1.100 g-1 in control and 34 +/- 33
ml.min-1.100 g-1 in adenosine-treated animals. No significant regional
structural differences were observed within the microvascular beds of the
two groups. The percentage of the microvascular volume perfused increased
significantly in all brain regions in the adenosine-treated rats, including
the flow-restricted cortex. The percent perfused arteriolar volume in the
flow-restricted cortex was 30 +/- 12% in control and 95 +/- 3% in
adenosine-treated animals. Similar values for the capillary bed were 22 +/-
10% in control and 54 +/- 3% in adenosine-treated rats. These results
indicate a maintenance of flow with a reduction in diffusion distances in
the flow-restricted cortex after treatment with adenosine.
