THE OUTPUT OF PROTEIN METABOLISM HORMONE OF THE PITUITARY ANTERIOR LOBE

Abstract

Protein feeding is followed by the output of a factor in the urine which, injected into rats, produces a decrease of blood urea N and of blood amino N. This factor is not present in the urine after a protein-free carbohydrate-fat diet. This reaction to inj. of urine following protein intake (decrease of N.P.N. constituents in the rat) is the same as is obtained by injecting alkaline extracts of the pituitary. The factor traced in the urine after protein feeding is probably of pituitary origin. A faptor of pituitary origin also prevents rise of blood amino N after a protein meal given 3 hrs. after a similar previous protein meal. Protein feeding is the adequate stimulus for the output of this hormone. Stimulation of the output of hormone by administering the substance on which the hormone specifically acts is not peculiar to protein metabolism. The same occurs in carbohydrate, fat and Ca metabolism and this mechanism apparently represents a general physiological rule.