THE EFFECT OF DIETARY PROTEIN CONTENT UPON THE NITROGEN RETENTION AND WEIGHT GAIN PRODUCED BY THE HYPOPHYSEAL GROWTH HORMONE

Abstract

The action of a standard daily dose of growth hormone for a 5-day injn. period on the body wt. and urinary N excretion of rats fed complete diets is characteristically as follows: (a) the N excretion promptly decreases, usually to the greatest extent in the 1st 24 hrs.; (b) the body wt. promptly increases; (c) upon cessation of injn., the N excretion promptly returns to the pre-injn. level or is slightly higher; (d) upon cessation of injn. approx. 20%-30% of the wt. gained is lost, the wt. usually reaching the lowest level on the 4th post-injn. day. The rats then regain wt. to "plateau" again on the 10th post-injn. day at or near the maximal wt. attained. The amt. of N retained and the increment of wt. gained under the influence of a 5-day injn. period of the hypophyseal growth hormone, both vary concordantly with the dietary protein content. The 24% casein diet is optimal for the dose of growth hormone which was employed. The amt. of N retained, calculated as protein plus protein-bound water, corresponds closely to the observed wt. gain.