Journal of Applied Physiology, Vol 52, Issue 4 1024-1029, Copyright © 1982 by American Physiological Society
Body fluid and hematologic adjustments during resting cold acclimation in rhesus monkey
I. R. Oddershede and R. S. Elizondo
The purpose of this study was to examine body fluid adjustments during
prolonged cold exposure in primates. Six male rhesus monkeys were
acclimated for 35 days and 6 degrees C and 80% rh. Red cell mass,
extracellular fluid volume, and total body water (TBW) were determined with
51Cr, 35SO4, and 3H2O, respectively, prior to and at various intervals
during the cold stress. TBW was increased throughout the exposure, whereas
changes in extravascular compartments had occurred within the 1st wk of
cold exposure, after which they returned to control values. An increased
concentration of blood constituents on day 1 was not accompanied by a
decrease in cardiovascular volume. Blood volume and plasma volume in
relation to TBW were significantly increased on day 3 and remained
increased during the remainder of the exposure. These cardiovascular volume
changes were accompanied by a significant hemodilution on day 3 and a
gradual return to control values. An increased plasma osmolality and
expansion of the erythrocytes (decrease in mean corpuscular hemoglobin
concentration) were observed throughout the cold stress. These data suggest
that the rhesus monkey may be an adequate primate model for studies of body
fluid adjustments, especially during prolonged cold exposure, in primates
in general, including the human.
