Biomaterial Database

Methylmalonic acid metabolism of germfree and conventional vitamin B-12 deprived rats fed precursors of methylmalonate. 1979

S C Chen, and S M Oace

Experiments using germfree (GF), ex-germfree (XGF) and conventional (CONV) rats were conducted to study the relationship of intestinal microorganisms to vitamin B-12 (B-12) status and to methylmalonic acid (MMA) excretion of the host animal, since B-12 depleted GF rats have been found to excrete less than expected level of urinary MMA. The possibility that the GF rat lacks sufficient precursor of MMA was tested by feeding GF, XGF and CONY rats diets low or high in MMA precursors and examining urinary excretion of MMA and formiminoglutamic acid at intervals. The possibility that the GF rat may metabolize propionate and MMA differently from the CONV rat was examined by a MMA loading-recovery study and a CO2 collection study after [14C]propionate injection. Plasma and tissue B-12 levels were determined at the beginning and the end of the study. Results indicate that 1) lack of sufficient precursor of MMA is partly responsible for the failure of GF, B-12 deficient rat to excrete MMA, 2) GF and CONV rats metabolize propionate and MMA by the same pathways and 3) the presence of intestinal microorganism depletes the body B-12 store of the rat.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008314	Malonates	Derivatives of malonic acid (the structural formula CH2(COOH)2), including its salts and esters.
D008764	Methylmalonic Acid	A malonic acid derivative which is a vital intermediate in the metabolism of fat and protein. Abnormalities in methylmalonic acid metabolism lead to methylmalonic aciduria. This metabolic disease is attributed to a block in the enzymatic conversion of methylmalonyl CoA to succinyl CoA.	Acid, Methylmalonic
D011422	Propionates	Derivatives of propionic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxyethane structure.	Propanoate,Propanoic Acid,Propionate,Propanoates,Propanoic Acid Derivatives,Propanoic Acids,Propionic Acid Derivatives,Propionic Acids,Acid, Propanoic,Acids, Propanoic,Acids, Propionic,Derivatives, Propanoic Acid,Derivatives, Propionic Acid
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D004044	Dietary Proteins	Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.	Proteins, Dietary,Dietary Protein,Protein, Dietary
D005856	Germ-Free Life	Animals not contaminated by or associated with any foreign organisms.	Axenic Animals,Gnotobiotics,Germfree Life,Animal, Axenic,Animals, Axenic,Axenic Animal,Germ Free Life,Gnotobiotic,Life, Germ-Free,Life, Germfree
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013025	Glycine max	An annual legume. The SEEDS of this plant are edible and used to produce a variety of SOY FOODS.	Soy Beans,Soybeans,Bean, Soy,Beans, Soy,Soy Bean,Soybean
D014806	Vitamin B 12 Deficiency	A nutritional condition produced by a deficiency of VITAMIN B 12 in the diet, characterized by megaloblastic anemia. Since vitamin B 12 is not present in plants, humans have obtained their supply from animal products, from multivitamin supplements in the form of pills, and as additives to food preparations. A wide variety of neuropsychiatric abnormalities is also seen in vitamin B 12 deficiency and appears to be due to an undefined defect involving myelin synthesis. (From Cecil Textbook of Medicine, 19th ed, p848)	Deficiency, Vitamin B 12,Deficiency, Vitamin B12,Vitamin B12 Deficiency,Deficiencies, Vitamin B12,Vitamin B12 Deficiencies