The effect of hypophysectomy of the rat and of treatment with growth hormone on the incorporation in vivo of radioactive amino acids into the proteins of subcellular fractions of rat liver

Publisher Website
Google Scholar
Abstract
The incorporation in vivo of injected radioactive amino acids into the total protein of rat liver and into the proteins of the nuclei, mitochondria, microsomes and soluble fraction is diminished by hypophysectomy. Treatment of hypophysectomized rats with ox growth hormone restored, in part, the diminished incorporation into the total proteins and the proteins of the subcellular fractions of rat liver, towards the normal values. These changes could not be ascribed to hormonally controlled changes in the specific activity of the intra-cellular amino acid pool. Separation of the microsomes into micro-somal particles and into material soluble in deoxycholate showed diminished ability of the microsomal particles of liver from hypophysectomized rats to incorporate amino acids into protein. The maximum specific activity of the protein of these particles was depressed as a result of hypophysectomy and was more slowly attained in normal rats. Treatment of the hypophysectomized rats with growth hormone reversed both these trends to some extent. The possible effects of hypophysectomy and subsequent treatment with growth hormone on different stages of protein synthesis are discussed.