Effect of pituitary extracts upon the work performance of adrenalectomized-hypophysectomized rats: identification of vasopressin as a principle affecting work.

Abstract

THE rat loses its capacity to work in response to faradic stimulation within a few hours following either adrenalectomy or hypophysectomy. Adrenalectomized rats will work normally when given continuous intravenous injections of adrenal cortical extract (ACE) whereas the performance of hypophysectomized and adrenalectomized-hypophysectomized rats is improved but not restored to normal by ACE. The performance of either hypophysectomized or adrenalectomized-hypophysectomized rats is restored to normal by the continuous intravenous injection of ACE plus certain preparations of corticotropin (Ingle, Nezamis and Morley, 1953; Ingle et al., 1953). The data of the present study show that various fractions of pituitary extracts contain this principle affecting work; that a fraction containing this principle is separable from corticotropin; this principle is not identical with any known anterior lobe hormone; and finally that minute amounts of vasopressin added to ACE will normalize the work of adrenalectomizedhypo...