AJP - Heart and Circulatory Physiology, Vol 234, Issue 6 706-H710, Copyright © 1978 by American Physiological Society
Blood flow distribution in dogs during hypothermia and posthypothermia
T. Anzai, M. D. Turner, W. H. Gibson and W. A. Neely
Blood flow distribution in tissues of mongrel dogs during hypothermia was
studied with radionuclide-tagged microspheres. The animals were cooled at
21 degrees C and rewarmed under thiamylal sodiuni anesthesia. During
hypothermia, cardiac output fell to 20% of the control; the highest rate of
blood flow relative to normothermic values was observed in the
subendocardium of the left ventricle, and the lowest in the hypophysis.
Each tissue showed specific reactions to hypothermia. During hypothermia
the myocardial and brain-stem blood flows were about 40% of the control;
almost all of the digestive tract, striated muscle, adrenal gland, and
hypophysis blood flows were maintained at 20% or less of the control. After
rewarming, cardiac output recovered to values significantly lower than
control. The myocardium, brain, renal cortex, and striated and smooth
muscle recovered to control levels; however, blood flow to the digestive
organs, bronchial artery flow to the lung, and flow to the endocrine organs
did not completely recover by 2 after rewarming.
