title: Effect of different amino acid diets on delta 5, delta 6 and delta 9 desaturases.
abstract: A high-protein diet with 45% calories from casein increased delta 6 desaturase activity in rat-liver microsomes. High-protein diets with 45% calories from a synthetic mixture of amino acids in the same proportion as casein decreased the delta 9 desaturase, slightly increased the delta 5 desaturase and greatly increased delta 6 desaturase activities compared with a high-carbohydrate diet. The elimination of phenylalanine and tyrosine from the synthetic mixtures of amino acids increased the delta 6 desaturase activity. Massive amounts of phenylalanine or tyrosine in the diet inhibited delta 6 desaturase activity. Tyrosine and phenylalanine may, by conversion to tyrosine, decrease the activity of the delta 6 desaturase.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D004032:Diet; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005260:Female; D008862:Microsomes, Liver / Q000378:metabolism; D010649:Phenylalanine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014443:Tyrosine / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D014443:Tyrosine; D010649:Phenylalanine; D044943:Fatty Acid Desaturases