AJP - Heart and Circulatory Physiology, Vol 258, Issue 4 1119-H1125, Copyright © 1990 by American Physiological Society
Regional circulatory responses to intestinal work in developing swine
N. M. Buckley and I. D. Frasier
Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York 10025.
Circulatory effects of intraduodenal feeding with 2 and 5% glucose were
studied in 29 fasted swine (1 day to 1 mo old) anesthetized with
pentobarbital. Recordings included aortic and intestinal venous pressures
and intestinal, renal, and femoral blood flows. Calculations included
vascular resistances, arterial and intestinal venous O2 contents, and
intestinal O2 consumption. Observations were made before and at 15 and 30
min after a feeding and at end of experiments. Blood flow autoregulation
was evaluated before and after feedings. Glucose induced increases in
intestinal O2 consumption and blood flow at all ages, but intestinal blood
flow autoregulation was enhanced only in 2 wk olds. Blood flow was
redistributed to the working gut from the hindlimb, but not the kidney, at
all ages. Renal blood flow autoregulation was sustained in 2-wk-old and
1-mo-old animals and became significant in 1 wk olds during intestinal
hyperemia. We concluded that basic mechanisms governing blood flow
redistribution from hindlimb to working gut are available at birth in swine
and that maintenance of renal blood flow depends only partly on
autoregulatory capability.
