Influence of high glycine diets on the activity of glycine-catabolizing enzymes and on glycine catabolism in rats

Journal Article · Thu May 01 04:00:00 EDT 1986 · J. Nutr.; (United States)

OSTI ID:5528335

Petzke, K J; Albrecht, V; Przybilski, H

Male albino rats were adapted to isocaloric purified diets that differed mainly in their glycine and casein contents. Controls received a 30% casein diet. In experimental diets gelatin or gelatin hydrolysate was substituted for half of the 30% casein. An additional group was fed a glycine-supplemented diet, which corresponded in glycine level to the gelatin diet but in which the protein level was nearly the same as that of the casein control diet. Another group received a 15% casein diet. Rat liver glycine cleavage system, serine hydroxymethyltransferase and serine dehydratase activities were measured. /sup 14/CO/sub 2/ production from the catabolism of /sup 14/C-labeled glycine was measured in vivo and in vitro (from isolated hepatocytes). Serine dehydratase and glycine cleavage system activities were higher in animals fed 30% casein diets than in those fed 15% casein diets. Serine hydroxymethyltransferase activity of the cytosolic and mitochondrial fractions was highest when a high glycine diet (glycine administered as pure, protein bound in gelatin or peptide bound in gelatin hydrolysate) was fed. /sup 14/CO/sub 2/ formation from (1-/sup 14/C)- and (2-/sup 14/C)glycine both in vivo and in isolated hepatocytes was higher when a high glycine diet was fed than when a casein diet was fed. These results suggest that glycine catabolism is dependent on and adaptable to the glycine content of the diet. Serine hydroxymethyltransferase appears to play a major role in the regulation of glycine degradation via serine and pyruvate.

• Research Organization: Central Institute of Nutrition, German Democratic Republic
• OSTI ID: 5528335
• Journal Information: J. Nutr.; (United States), Journal Name: J. Nutr.; (United States) Vol. 5; ISSN JONUA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BODY
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBON-OXYGEN LYASES
CARBOXYLIC ACIDS
CASEIN
CATABOLISM
CHALCOGENIDES
DIET
DIGESTIVE SYSTEM
ELEMENTS
ENZYME ACTIVITY
ENZYMES
GLANDS
GLYCINE
HYDRO-LYASES
LABELLED COMPOUNDS
LIVER
LYASES
MAMMALS
METABOLISM
NITROGEN
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PROTEINS
RATS
RODENTS
TRANSFERASES
VERTEBRATES