AJP - Gastrointestinal and Liver Physiology, Vol 256, Issue 2 364-G368, Copyright © 1989 by American Physiological Society
Postprandial gastrointestinal blood flow and oxygen consumption during environmental cold stress
S. R. Mayfield, W. Oh, D. L. Piva and B. S. Stonestreet
Program in Medicine, Brown University, Providence, Rhode Island.
We studied the independent and combined effects of feeding and
environmental cold stress by measuring pre- and postprandial
gastrointestinal blood flow (QGI), oxygen consumption (GIVO2), and oxygen
extraction (GIO2ex) in seven awake 3- to 4-day-old piglets while in a
thermoneutral environment (control phase, 31 degrees C) and during
environmental cold stress (experimental phase, 20.5 degrees C). Each animal
consecutively completed both the control and experimental phases. In the
control phase, measurements were made before and 30 min after feeding. In
the experimental phase, measurements were made before and 30 min after
induction of cold stress. A feeding was then given and measurements
repeated 30 min later during continued cold stress. QGI (ml.100 g-1.min-1)
increased postprandially while in a thermoneutral environment (130 +/- 11
to 152 +/- 12) but not while in a cold environment (126 +/- 15 to 121 +/-
8). Postprandial GIVO2 (ml O2.100 g-1.min-1) increased from 2.1 +/- 0.2 to
3.7 +/- 0.5 while in a warm environment. During preprandial cold stress, an
unexpected increase in GIVO2 was observed (1.7 +/- 0.2 to 3.1 +/- 0.5).
Feeding while in a cold environment provoked a further significant increase
in GIVO2 (3.1 +/- 0.5 to 4.2 +/- 0.4). All increases in GIVO2 were
associated with increased GIO2ex. This study has demonstrated that 1)
postprandial GIVO2 is appropriately increased during cold stress as a
function of GIO2ex and 2) that fasting GIVO2 is increased during cold
stress, demonstrating an intestinal metabolic contribution to cold-induced
systemic thermogenesis.
