AJP - Regulatory, Integrative and Comparative Physiology, Vol 270, Issue 5 1099-R1108, Copyright © 1996 by American Physiological Society
Interaction of type I and type II corticosteroid receptor stimulation on carcass energy and carcass water
B. D. White, G. L. Edwards and R. J. Martin
Department of Foods and Nutrition, University of Georgia, Athens 30602, USA.
The effects of chronic type I and type II corticosteroid receptor
stimulation were examined in adrenalectomized Sprague-Dawley rats to
quantify the relative contribution of body energy and body water changes to
changes in body weight. Adrenalectomy caused a decrease in both body energy
and water. Aldosterone (type I agonist) treatment increased body weight
gain and returned energy accretion to the level of sham-operated animals.
However, most of the change in body weight (72%) was attributable to a
change in body water. The aldosterone-induced increase in body weight gain
and carcass water were attenuated by RU-28362 (type II receptor agonist)
infusion, suggesting that type II receptor stimulation can antagonize the
effect of type I receptor stimulation. Changes in carcass water were
paralleled by changes in soluble carcass sodium. Despite alterations in
soluble body sodium, no measurable differences in cumulative sodium
retention were found. These findings confirm previous studies suggesting an
effect of type I receptor stimulation on energy accretion. However, they
also caution that changes in body weight cannot be equated with changes in
body energy.
