AJP - Gastrointestinal and Liver Physiology, Vol 251, Issue 3 308-G313, Copyright © 1986 by American Physiological Society
Regional blood flow in newborn piglets during environmental cold stress
S. R. Mayfield, B. S. Stonestreet, A. M. Brubakk, P. W. Shaul and W. Oh
Regional blood flow, oxygen delivery, and vascular resistance were
determined in newborn piglets during a successful homeothermic response to
environmental cold stress. Eight 3- to 4-day-old awake piglets were studied
in a thermoneutral environment and 30, 45, and 60 min after onset of
environmental cold stress. During cold stress, blood flow was significantly
increased to skeletal muscle, the thermogenic organ, and decreased to the
small intestine (P less than 0.05). Because arterial oxygen content (CaO2)
was stable during the study, changes in oxygen delivery (CaO2 X blood flow)
paralleled blood flow. Vascular resistance during cold stress was
significantly decreased in skeletal muscle and increased in both the
adrenals and the small intestine (P less than 0.05). We conclude that,
during successful thermogenesis, the redistribution of cardiac output
toward the thermogenic organ (skeletal muscle) is associated with a
significant decrease in intestinal blood flow and oxygen delivery. This is
not a passive process as evidenced by the coincident observation of
increased intestinal vascular resistance.
