Purine nucleotide synthesis from exogenous adenine and guanine in rodent small intestine
/sup 14/C-Adenine and /sup 14/C-guanine uptake was studied in isolated guinea pig enterocytes. Cells were incubated in Hank's buffer and separated from the medium by centrifugation through silicone oil into 1M PCA. Uptake was temperature and concentration dependent. Both compounds were incorporated into nucleotides as measured by HPLC and HVE. Adenine was more extensively incorporated into nucleotides than was guanine. Adenine nucleotides accounted for about 70% of the intracellular label after 30 min with a majority being ADP and ATP (medium concentration = 10 ..mu..M). Guanine nucleotides accounted for only 30% of the intracellular label after 30 min. Labeled intracellular free adenine or guanine were not detected. Significantly more guanine vs. adenine was converted to uric acid. After 30 min, 11.5 +/- 3.9% (n=3) and 83.0 +/- 8.4% (n=4) of the label was present as uric acid in the medium when adenine and guanine, respectively, were the substrate. After 1 min, 34.8 +/- 3.4% (n=4) of the label in the medium was present as uric acid when guanine was the substrate. Decreasing the concentration of adenine resulted in an increase in the percent of uric acid in the medium. /sup 14/C-adenine (75 nmol) was injected into 1 gm segments of rat jejunum. After 5 min., segments were quickly flushed and the tissue homogenized in 1M PCA. Only uric acid was present after 5 min (n=6). In contrast, in animals fasted 3 to 5 days, less conversion to uric acid was observed in the intestinal content (50-80% of the same dose was still present as adenine after 5 min) and nucleotide formation was observed in the tissue. The results indicate that uric acid and nucleotide synthesis from exogenous adenine and guanine are concentration dependent and affected by nutritional state.
- Research Organization:
- Univ. of Minnesota, St. Paul
- OSTI ID:
- 5325592
- Report Number(s):
- CONF-8604222-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:3; ISSN FEPRA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
ADENINES
ADP
AMINES
ANIMALS
ANTIMETABOLITES
AROMATICS
ATP
AZAARENES
BIOSYNTHESIS
BODY
CARBON 14 COMPOUNDS
DIGESTIVE SYSTEM
DRUGS
GASTROINTESTINAL TRACT
GUANINE
GUINEA PIGS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INTESTINES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PURINES
RATS
RODENTS
SMALL INTESTINE
SYNTHESIS
TEMPERATURE DEPENDENCE
TRACER TECHNIQUES
UPTAKE
VERTEBRATES