Possible Water Balance;Effects of Alkaline Anterior Pituitary Extracts

Abstract

In these studies an inbred strain of well-standardized mice were used as experimental animals. Feeding and environmental conditions were made as nearly identical throughout as possible. The experiments continued over a period of 8 months, and included many series of animals injected and handled under a wide variety of conditions, but with each experiment carefully controlled. In each case the group was divided into animals receiving the alkaline extract of the anterior lobe, a group receiving the ammonium sulphate extractive, and a group of controls. In some of the experiments, the controls received an alkaline liver extract, on others, normal saline, while in a few cases no injections were given the controls. In some cases the dosages were very minute and given only once a day; from this, they varied to 3 times a day and very large dosages. In some series, all of the animals received unlimited quantities of fluid—water or milk, or both; in others, the fluid intake was sharply curtailed. This series of studies reveals the following facts:

Immature animals injected with the alkaline extract, as outlined by Evans, 1 gain weight at a more rapid rate than do the ammonium sulphate extractive injected animals or the controls, provided the allowance of fluid is unlimited or large. The animals receiving the ammonium sulphate extractive gain weight slightly more rapidly than do the control animals. If the fluid intake be sharply curtailed, the animals receiving the alkaline extract do not gain weight as rapidly as do the control animals, or the ammonium sulphate animals. Under these conditions, however, the ammonium sulphate injected animals gain weight more rapidly than do the controls. If, after a long-continued period of injections, when the alkaline extract injected animals have gained a great amount in weight, the fluid intake be suddenly stopped, their weights will drop to near the average weight of the control animals in a period of 24 to 48 hours.