UBC Theses and Dissertations
The metabolism of 2-C¹⁴-adenine in the adult male rat Paterson, Alan Robb Phillips
Isotopic adenine, labeled with C¹⁴ in position 2, has been prepared in three steps; (a) formylation of 4-amino - 5-imidazolecarboxamidine in aqueous C¹⁴-formic acid, (b) ring closure of the resulting formamido compound to form 2-C¹⁴-adenine, (c) purification by sublimation in vacuo. The overall yield for the three operations was 60 percent. Proof of identity of the adenine prepared in this manner was obtained from the preparation of a derivative, combustion analysis, paper chromatography and ultraviolet spectrophotometry. The metabolism of 2-C¹⁴-adenine was studied in the adult male rat. The labeled compound was administered to the experimental animals by intraperitoneal injection. The isotope of the administered adenine was found distributed in the purines of the visceral nucleic acids, the expired carbon dioxide and urine, where part of the activity was found in both urea and allantoin. Nucleic acid adenine and guanine were synthesized to the extent of 7.7 percent and 5.5 percent respectively from administered 2-C¹⁴-adenine. The adenine renewal is lower than similar values derived from 1,3-N¹⁵-adenine as reported in the literature. Expired carbon dioxide was found to contain over 8 percent of the administered isotope. Combustion analyses of whole urine indicated that 28 percent of the administered isotope was contained therein. Urea and allantoin together accounted for 16-29 percent of the total radioactivity in urine. The presence of radioactive carbon dioxide in the expired air of the experimental animals, when considered in the light of other evidence, is regarded as being indicative of a biological lability in position 2 of the purines.
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