Effect of amino acids on liver RNA synthesis in the chick
Herbert, J.A.; Teekell, R.A.; Watts, A.B.
Journal of Nutrition 102(8): 987-993
1972
ISSN/ISBN: 0022-3166 PMID: 5051863 Document Number: 50570
Chicks 2 weeks old were given by mouth mixtures of different kinds and amounts of amino acids. The effect of these amino acids on RNA synthesis was measured by the incorporation of tritium from uridine-5-3H into RNA of the chick liver. High intakes of amino acids (300 mg) decreased RNA synthesis. Of the precursors of the purine ring tested (folic acid, glycine, glutamine and aspartic acid), only aspartic acid had any effect on RNA synthesis. It increased the synthesis of RNA. When given in different amounts, 20 mg of aspartic acid/chick promoted the highest amount of RNA synthesis, but 40 mg of aspartic acid decreased the synthesis of RNA. Amino acid imbalances generally lowered both RNA and protein synthesis when compared with a completely balanced amino acid mixture. Of the imbalances tested by estimating the incorporation of 14C from glycine-1-14C into RNA and protein, a deficiency of tryptophan seemed to have the greatest effect. The data indicate that amino acids will increase the synthesis of RNA when administered at recommended dietary intakes but will decrease synthesis of RNA when given at excessively high intakes or as imbalanced mixtures.