Control of ornithine decarboxylase activity in rat colon by two stimuli known to synergistically induce the enzyme
The authors have previously shown a synergistic induction of rat colon ornithine decarboxylase (ODC) by sodium deoxycholate (NaDOC) instillation and starving-refeeding (S/R). Possible explanations include specific increases in ODC synthesis, general increases in protein synthesis rates, substrate level changes, and cofactor availability (pyridoxal-5'-phosphate, PLP). The present studies examine these possibilities and the effects of the two stimuli on polyamine levels. The following measures were made over the 18 h period following each stimulus: rates of general protein synthesis using /sup 3/H-leucine incorporation; ODC, ornithine aminotransferase (OAT), and ornithine transcarbamylase activities; and concentrations of ornithine, the polyamines, PLP, DNA, and total RNA. After NaDOC instillation, one peak of ODC activity was seen at 4 h, with a slight nonsignificant decrease in overall protein synthesis rate. After S/R, peaks of ODC activity were seen at 4 and 12 h, the first peak being accompanied by increased putrescine and decreased spermine levels. The second peak was accompanied by increased OAT activity. These results are consistent with an increase in general protein synthesis rate being responsible for the ODC activity increase seen after S/R, but not after NaDOC instillation.
- Research Organization:
- Cornell Univ., Ithaca, NY
- OSTI ID:
- 5096620
- Report Number(s):
- CONF-8606151-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DECARBOXYLASES
ENZYME ACTIVITY
PROTEINS
BIOSYNTHESIS
ENZYME INDUCTION
LARGE INTESTINE
LEUCINE
ORNITHINE
RATS
STIMULI
SYNERGISM
TRACER TECHNIQUES
TRITIUM COMPOUNDS
AMINO ACIDS
ANIMALS
BODY
CARBON-CARBON LYASES
CARBOXY-LYASES
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
ENZYMES
GASTROINTESTINAL TRACT
GENE REGULATION
INTESTINES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYASES
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RODENTS
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques