Dietary sulfur amino acid modulation of cysteine sulfinic acid decarboxylase

Male rats were fed sulfur and nonsulfur amino acid-supplemented diets, and the response of cysteine sulfinic acid decarboxylase (CSAD) activity was determined. After adaptation to a casein-based basal diet, rats were fed diets containing additions of L-methionine. Hepatic CSAD activity decreased in...

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Bibliographic Details
Published inThe American journal of physiology Vol. 261; no. 5; p. E551
Main Authors Jerkins, A.A. (University of Wisconsin, Madison, WI), Steele, R.D
Format Journal Article
LanguageEnglish
Published United States 01.11.1991
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Summary:Male rats were fed sulfur and nonsulfur amino acid-supplemented diets, and the response of cysteine sulfinic acid decarboxylase (CSAD) activity was determined. After adaptation to a casein-based basal diet, rats were fed diets containing additions of L-methionine. Hepatic CSAD activity decreased in a dose-dependent manner. Significant depression of CSAD activity in liver was evident within 24 h of feeding rats a methionine-supplemented diet. Depression of enzyme activity was reversed upon refeeding the basal diet. After rats were fed diets supplemented with methionine, cystine, homocystine, S-methyl-L-cysteine, phenylalanine, leucine, or ethionine for 14 days, hepatic CSAD activity in rats fed S-methyl-L-cysteine-, phenylalanine-, or leucine-supplemented diets was not depressed compared with activity in rats fed a basal diet. In contrast, CSAD activity in livers of rats fed cystine-, homocystine-, methionine-, or ethionine-supplemented diets was 60, 40, 40, and 8%, respectively, of the activity in livers from control rats. Immunochemical detection and quantification of CSAD protein in rat liver indicated that CSAD protein concentration was correlated to CSAD activity. CSAD activity may be specifically regulated by sulfur amino acids metabolized by the S-adenosylmethionine-dependent pathway of methionine metabolism
Bibliography:S20
9177429
ISSN:0002-9513
2163-5773
DOI:10.1152/ajpendo.1991.261.5.E551