Influence of casein and soy flour proteins on aminoacid content in the liver of experimental animals.
We have observed a significantly increased content of fats and decreased content of proteins in the liver of experimental rats fed a diet supplemented with 25% casein proteins in comparison with the application of de-fatted soy flour. Casein proteins have a higher content of methionine in relation to cystine than baked soy flour. But the soy diet in contrast to the casein diet has a high content of free aminoacids which are not present in casein at all: aspartic acid, asparagine, alpha-aminoadipic acid, methionine, norleucine, lysine, phenylalanine, beta-alanine, ethanolamine, histidine, proline, gamma-aminobutyric acid, taurine. Differences in free valine, alanine, arginine, glycine, ornithine and cysteic acid are also significant. The content of free aminoacids in the liver of experimental animals fed a soy diet is high in the content of cystine, cystathionine, ornithine, beta-aminoisobutyric acid, beta-alanine, gamma-aminobutyric acid, leucine. We have also found accumulation of methionine, glycine, alpha-aminobutyric acid, taurine and citrulline in free aminoacids from the liver of animals fed a casein diet. Citrulline and glycine in free aminoacids from the liver of animals fed a soy protein supplement were not recorded. Our investigations have shown that the application of a soy diet enriched with cystine acts protectively on methionine and that methionine is preferentially utilized for protein synthesis. The catabolic pathway of methionine prevails in animals on a casein diet.
Dudásová
S
S
Research Institute of Human Nutrition, Bratislava.
Grancicová
E
E
D000409:Alanine / Q000032:analysis; D000596:Amino Acids / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D001216:Asparagine / Q000032:analysis; D001224:Aspartic Acid / Q000032:analysis; D002364:Caseins / Q000032:analysis / Q000494:pharmacology*; D003553:Cystine / Q000032:analysis; D004044:Dietary Proteins / Q000032:analysis / Q000494:pharmacology; D005527:Food, Fortified; D005998:Glycine / Q000032:analysis; D008099:Liver / Q000737:chemistry* / Q000378:metabolism; D008715:Methionine / Q000032:analysis; D009646:Norleucine / Q000032:analysis; D009952:Ornithine / Q000032:analysis; D014674:Plant Proteins, Dietary / Q000032:analysis / Q000494:pharmacology*; D051381:Rats; D030262:Soybean Proteins; D013654:Taurine / Q000032:analysis
D000596:Amino Acids; D002364:Caseins; D004044:Dietary Proteins; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins; D013654:Taurine; D001224:Aspartic Acid; D003553:Cystine; D001216:Asparagine; D009646:Norleucine; D008715:Methionine; D009952:Ornithine; D000409:Alanine; D005998:Glycine