ALLOXAN DIABETES AND IN VITRO PROTEIN BIOSYNTHESIS IN RAT LIVER MICROSOMES AND MITOCHONDRIA

Abstract

SUMMARY 1. Mitochondria and microsomes isolated from livers of alloxan-diabetic rats incorporate less radioactive amino acid into their proteins in vitro than the corresponding subcellular particles prepared from livers of normal rats. 2. Most of the decrease in incorporation of amino acids shown by the microsome system prepared from alloxan-diabetic rats is caused by alterations in the ability of the microsomes to assemble amino acids into polypeptide chains, but some depressing effect on the ability of the soluble fraction of the liver cells to prepare acids for incorporation is also found in alloxan-diabetic rats. 3. Treatment of alloxan-diabetic rats with insulin restored towards normal the depressed ability of both mitochondria and microsomes to incorporate amino acids into protein in vitro. 4. Treatment of alloxan-diabetic rats with small doses of growth hormone increased the incorporation of amino acids into protein by mitochondria and microsomes in vitro, but treatment of the rats with larger doses of growth hormone resulted in further depression of the in vitro incorporating ability of both subcellular particles.