Studies on polyamine and ornithine metabolism in rat colon: effects of two synergistically. Acting inducers of ornithine decarboxylase activity

Thesis/Dissertation · Wed Dec 31 23:00:00 EST 1986

OSTI ID:7001970

Stanley, B A

Ornithine decarboxylase (ODC) activity in rat colon mucosa was determined by the release of /sup 14/CO/sub 2/ from radiolabeled ornithine in the presence (total enzyme) or absence (holoenzyme) of added pyridoxal-5'-phosphate (PLP). Total leucine incorporation into acid-precipitable protein over 30 minute was calculated by dividing the /sup 3/H-leucine in protein by the specific activity of the intracellular leucine. Amino acids, polyamines, and PLP-semicarbazide were quantified by high pressure liquid chromatography. Ornithine aminotransaminase activity (OAT) was measured as the quantity of pyrolline (5-carboxy) produced from alpha-ketoglutarate and ornithine. After 10 weeks on a high or no vitamin B/sub 6/ diet, no change in basal ODC activity was seen; however, sodium deoxycholate instillation in vitamin B/sub 6/ deficient rats led to a large increase in total but not holo-ODC activity. In rats fed normal chow diet, no increases in mucosal PLP levels were seen after either treatment. Increases in general protein synthesis rate could not account for the peaks in ODC activity after either stimulus. Putrescine increases were proportional to peaks of ODC activity after either stimulus, while spermine levels remained depressed for 18 hours after starvation/refeeding. Ornithine levels were increased after either stimulus, and this increase was linked to decreases in OAT activity, indicating short-term coordination of overall ornithine metabolism to favor polyamine biosynthesis.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 7001970
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
560300 -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINES
AMINO ACIDS
AMINOTRANSFERASES
ANIMALS
AZINES
BODY
CARBON 14 COMPOUNDS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBON-CARBON LYASES
CARBOXY-LYASES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHROMATOGRAPHY
DECARBOXYLASES
DIET
DIGESTIVE SYSTEM
ENZYME ACTIVITY
ENZYME INDUCTION
ENZYMES
FASTING
GASTROINTESTINAL TRACT
GENE REGULATION
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INTESTINES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LARGE INTESTINE
LEUCINE
LIQUID COLUMN CHROMATOGRAPHY
LYASES
MAMMALS
METABOLISM
NITROGEN TRANSFERASES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
ORNITHINE
OXIDES
OXYGEN COMPOUNDS
PROMOTERS
PROTEINS
PUTRESCINE
PYRIDINES
PYRIDOXINE
RATS
RESPONSE MODIFYING FACTORS
RODENTS
SEPARATION PROCESSES
SYNERGISM
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
TUMOR PROMOTERS
VERTEBRATES
VITAMIN B GROUP
VITAMINS