Fetal Bile Salt Metabolism

Comparison with the results of similar experiments in adult dogs showed that the fetal liver was almost as efficient as the adult liver in the uptake, conjugation, and excretion of tracer amounts of cholate-"C. The maximal rate of excretion of radiolabel attained by the fetus was somewhat slower than in the adult (82.8 ±1.4% and 96.1 ±4.0% [mean +SE] of the infusion rate, respectively), and the proportion of the total dose excreted by the fetal liver during 10 hr was smaller (81.4 ±1.3% vs. 96.6 ±4.4%). This difference could be only partly accounted for by placental transfer (2.8 ±0.6% of the fetal dose). Labeled cholate and taurocholate were excreted by the fetus at similar rates, which suggests that, under the conditions of study, conjugation had little influence on the rate of transfer of cholate across the liver cell. It is concluded that the fetal dog, 1 wk before birth, This work was partially completed during the tenure of an Established Investigatorship of the American Heart Association held by Dr. Jackson. Dr. Lester is the recipient of U. S. Public Health Service Career Development Award AM 12,127. Received for publication 1 June 1970 and in revised form 17 February 1971. has a remarkably mature and efficient the uptake and excretion of cholate. mechanism for