Influence of adrenal cortex on body water distribution in rats

Abstract

Body water distribution was determined in rats by the dilution of serum albumin-I¹³¹ and Br⁸² and by desiccation. Methylprednisolone (MP) increased the plasma and intracellular compartments and decreased the interstitial volume in intact hydrated rats. The body water moved in the opposite direction in the adrenalectomized, salt-maintained rats, and MP prevented this movement in terms of intracellular and interstitial volumes. Adrenalectomized rats which were salt depleted had an increased intracellular volume with water coming from both extracellular compartments, and MP had no effect in this group. The effect of deoxycorticosterone acetate was to increase plasma volume in the intact hydrated and in both adrenalectomized groups. The relationship between these changes in body water distribution, hematocrit, and plasma osmolality and sodium concentrations has been discussed.