title: Evidence for loss of tritium from 3 beta-tritiated deoxycholic acid during enterohepatic cycling in man.
abstract: A double-label single-intubation isotope technique was assessed for studying deoxycholic acid metabolism by simultaneous IV administration of [3 beta-3H]deoxycholic acid and [24-14C]deoxycholic acid to five healthy subjects. The 3H/14C ratio in duodenal bile fell progressively in all subjects, the mean reduction on day four being 48.8%. When the same labeled bile acids were administered to three ileostomy subjects, again the ratio fell with a mean reduction of 44.4% on day four. This fall more likely was due to hepatic exchange of tritium for hydrogen, rather than to colonic bacterial oxidation. [3 beta-3H]Deoxycholic acid should not be used to study the kinetics and metabolism of deoxycholic acid.
authors.affiliation: Department of Medicine, University of California, San Diego, La Jolla 92093.
authors.forename: S N
authors.initials: SN
authors.lastname: Marcus
authors.forename: K W
authors.initials: KW
authors.lastname: Heaton
mesh_terms: D000328:Adult; D002250:Carbon Radioisotopes; D003840:Deoxycholic Acid / Q000378:metabolism*; D004355:Drug Stability; D004764:Enterohepatic Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014316:Tritium / Q000378:metabolism*
chemical_list: D002250:Carbon Radioisotopes; D003840:Deoxycholic Acid; D014316:Tritium