AJP - Gastrointestinal and Liver Physiology, Vol 247, Issue 5 468-G479, Copyright © 1984 by American Physiological Society
Gastric blood flow determination: intramural distribution and arteriovenous shunting of microspheres
J. E. Varhaug, K. Svanes, C. Svanes and J. Lekven
Total and regional gastric blood flows were measured in 23 anesthetized
cats by labeled 10-micron (range 8-12 microns) and 15-micron (range 12-20
microns) microspheres. Total blood flow correlated closely with the gastric
venous outflow. Flow estimates by 10-microns spheres were 2.95% lower than
simultaneous 15-micron estimates. Approximately 2% of the 10-micron spheres
and 0.1% of the 15-micron spheres were shunted through the gastric
vasculature. The diameter distribution of 6,245 embolized spheres, measured
by microscopy, corresponded to that of the injectate, except for a lack of
the smallest spheres. Within the mucosa, the 10-microns spheres
predominantly lodged in the glandular layer, whereas larger spheres
gradually lodged more basally; 50% of the 15-microns population appeared in
the lamina propria below the gland bases. Vasodilation did not alter the
intramucosal distribution. Spheres in the subglandular lamina propria
represented blood flow mainly to the glandular layer. It is therefore
essential for reliable estimation of blood flow to the glandular layer of
the mucosa that the lamina propria is completely included in the specimens.
The submucosa contained only 0.5% of the 10-microns and 2.2% of the
15-micron embolized spheres. Spheres of 10.5-17 microns in diameter are
considered the most suitable for determination of gastric blood flow.
