Turnover of (/sup 14/C)thiamin and activities of thiamin pyrophosphate-dependent enzymes in tissues of mice with Ehrlich ascites carcinoma

Journal Article · Sun Jan 01 00:00:00 EST 1984 · Nutr. Cancer; (United States)

OSTI ID:5232864

Trebukhina, R V; Ostrovsky, Y M; Shapot, V S; Mikhaltsevich, G N; Tumanov, V N

Turnover of (/sup 14/C)thiamin was studied in mice with Ehrlich ascites carcinoma fed a thiamin-deficient diet and injected with 5 or 2 micrograms/mouse of the labeled vitamin. The process of conversion of (/sup 14/C)thiamin to thiamin pyrophosphate (TPP) was monitored by measuring the activities of transketolase, pyruvate dehydrogenase, and oxoglutarate dehydrogenase. The amount of coenzyme-unsaturated apotransketolase was assessed by measuring the TPP effect--determining transketolase activity with and without the addition of TPP in vitro. Tumor growth was accompanied by thiamin deficiency, manifested in an increase in (/sup 14/C)thiamin incorporation into the host tissues and the absence of saturation of the tissues with the labeled vitamin over 13 days. Increased values for the turnover coefficients, reduction of thiamin-dependent enzyme activities, elevation of the TPP effect, and a decrease in urinary excretion of the radioactive products also provided evidence for a disturbance in thiamin metabolism. The severity of the disturbance in thiamin metabolism during malignant tumor growth was directly related to the dose of the exogenous vitamin.

• Research Organization: Division of Metabolic Regulation, Grodno, USSR
• OSTI ID: 5232864
• Journal Information: Nutr. Cancer; (United States), Vol. 4
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
THIAMINE
METABOLISM
ASCITES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MODELS
CARBON 14 COMPOUNDS
EXPERIMENTAL NEOPLASMS
MICE
TISSUE DISTRIBUTION
TRACER TECHNIQUES
VITAMINS
AMINES
ANIMALS
AZINES
AZOLES
DISTRIBUTION
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PATHOLOGICAL CHANGES
PYRIMIDINES
REACTION KINETICS
RODENTS
SYMPTOMS
THIAZOLES
VERTEBRATES
VITAMIN B GROUP
550501* - Metabolism- Tracer Techniques