AJP - Regulatory, Integrative and Comparative Physiology, Vol 240, Issue 5 319-R326, Copyright © 1981 by American Physiological Society
Sodium metabolism during acclimation to water restriction by wild mice, Mus musculus
T. M. McKenna and H. Haines
Changes in sodium and potassium balance and urinary aldosterone excretion
(free plus "acid labile") were surveyed in house mice acclimating initially
to 1/2 the ad libitum water ration and later to 1/4 of ad libitum. Each
water restriction caused negative sodium and potassium balance, followed by
conservation of both ions. At the first water restriction, negative balance
was produced by natriuresis and kaliuresis, at successive water
restriction, a negative balance was due to a decrease in food consumption.
Aldosterone excretion doubled at the 1/2 ad libitum restriction, and then
generally remained at control levels thereafter. Fractional intestinal
absorption of both ions showed a persistent increase after the 3rd day of
water restriction. The Na:K ratio in urine and feces declined as mice
responded to each water restriction and returned to control levels in
acclimated animals.
