EFFECT OF CHRONIC INANITION ON THE GONADOTROPHIC CONTENT OF THE PITUITARY GLAND

Abstract

Low calory diets of bread and milk admd. for 30 days to young albino rats (avg. initial wt., 100 g.) produced a loss in wt. of approx. 35%, regressive changes in the ovaries, and interruption of the estrus cycle. Injn. of chorionic and pituitary gonadotropins reestablished estrus and induced regeneration of ovarian tissue. Parabiosis of underfed rats with normal rats not only failed to re-establish estrus but interrupted the sexual cycle of the normal animals. To assay gonadotropic potency, young mature albino rats were hypophysectomized and after a period of 14 days observation, 11 rats of almost identical wt. were obtained. Six rats were injd. daily with 1.5 mg. of a suspension of dried pituitary anterior lobe extract obtained from 200 mature rats which had been underfed for 30 days, and 5 received the same dose of normal anterior lobe extract. After 14 days'' injn. the wt. of the ovaries was 400% greater in those injd. with inanition pituitary gland, and histological regeneration of the ovaries was more evident than in those injd. with normal gland extracts. It is concluded that the pituitary anterior lobe stores gonadotropins during inanition which are not released into the circulation.