AJP - Gastrointestinal and Liver Physiology, Vol 252, Issue 2 190-G194, Copyright © 1987 by American Physiological Society
Intestinal blood flow and oxygen uptake in the neonatal piglet during reduced perfusion pressure
P. T. Nowicki, N. B. Hansen and J. A. Menke
The effect of reduced perfusion pressure on neonatal intestinal blood flow,
vascular resistance, arterio-venous oxygen content (a-v O2), and oxygen
uptake was studied in nine fasted newborn piglets, aged 5-6 days.
Successive reductions of intestinal perfusion pressure were achieved by a
clamp on the thoracic aorta. Intestinal blood flow decreased after each
reduction of perfusion pressure. Intestinal vascular resistance increased
and Gf, a measure of flow control, was negative after all but the final,
most severe reduction of perfusion pressure. However, intestinal a-v O2
increased after each pressure reduction and intestinal oxygen uptake was
thus maintained at greater than or equal to 95% of its baseline value until
perfusion pressure was reduced to less than or equal to 70% of its
base-line value. The neonatal intestine maintains tissue oxygen uptake
during moderate hypotension, and this is accomplished by regulation of a-v
O2, rather than by regulation of blood flow.
