THE EFFECTS OF PITUITARY GROWTH HORMONE ON THE METABOLISM OF ADMINISTERED AMINO ACIDS IN NEPHRECTOMIZED RATS1

Abstract

The anterior pituitary growth hormone is known to promote the retention of nitrogen in the body. This effect is best seen when observations are made in animals fed adequate protein over a day or more. Anterior pituitary extracts will lower the plasma amino nitrogen of fasted animals within a few hours, an effect presumably also the result of growth hormone action. From the conditions of these experiments, it is not possible to say whether the effects seen are due to suppression of protein catabolism or to an increase in the rate of protein anabolism. An acute effect of the growth hormone on the retention of administered nitrogen has not heretofore been demonstrated. In the present experiments, the rate of increase of urea in the blood of nephrectomized rats has been used as a measure of the rate of protein metabolism. A mixture of amino acids in the form of a casein hydrolysate was given intravenously,