Some effects of dehydration on internal distributions of water and solutes in Xenopus laevis

Abstract

1. 1. In relation to body weight changes resulting from evaporative water losses of up to 37% of initial body weight: 1.1. (a) Plasma chloride and potassium concentrations increased in proportion to total body water losses. 1.2. (b) Plasma urea concentrations increased at greater rates than expected from the sum of basal synthesis and dehydration. 1.3. (c) Plasma sodium concentrations initially increased less rapidly than expected from total body water losses, but by losses of 30% of initial body weight closely approximated predicted concentrations. 1.4. (d) Plasma volumes decreased slightly faster than expected, while hematocrits increased as expected. 2. 2. Skeletal muscles and the ventricular muscles of the heart retained water to greater degrees than expected. Dehydration did not elicit net shifts in Na + K +, Cl − or amino acids between the intracellular and extracellular compartments in either skeletal muscle or ventricle.