The Formation of Deoxycholic Acid and Chenodeoxycholic Acid in Man

1. The turnover of deoxycholic acid and chenodeoxycholic acid was studied in six normolipaemic patients after oral administration of trace amounts of isotopically labelled compounds. 2. The mean values for half-life, pool size and turnover of deoxycholic acid were 3·0 days, 663 mg and 171 mg/day respectively. The corresponding values recorded for chenodeoxycholic acid were 2·8 days, 781 mg and 207 mg/day. 3. A comparison of the turnover rates of deoxycholic acid and cholic acid in three subjects indicated that 25–61% of the cholic acid was converted into deoxycholic acid. 4. Only trace amounts of radioactivity were recovered in the trihydroxycholanic acid fraction of duodenal bile after the administration of [14C]deoxycholic acid or [3H]chenodeoxycholic acid.