THE EFFECT OF GROWTH HORMONE ON TIBIA GLYCOGEN CONTENT OF THE HYPOPHYSECTOMIZED RAT1

Abstract

The glycogen content of the tibia from young normal, hypophysectomized, and growth hormone-treated hypophysectomized rats was presented. The glycogen content of the tibia from immature hypophysectomized rats was found to decrease after operation more markedly than in unoperated animals of corresponding age, and reached a constant low level about 2 weeks postoperative. By treating hypophysectomized rats with growth hormone daily for 1-3 weeks after operation, it was possible to maintain the glycogen content of the tibia at normal or higher levels. The admn. of growth hormone to hypophysectomized rats already possessing a low content of tibia glycogen increased this to normal when given in sufficiently large doses. 24 hrs. of fasting did not further alter the low glycogen content of the tibia in hypophysectomized rats, nor was there any detectable change when growth hormone was administered during the fast.