Fetal bile salt metabolism: placental transfer of dihydroxy bile salts in sheep.
The bidirectional placental transfer of sodium [11,12-di-3H]chenodeoxycholate and sodium [14C]deoxycholate was studied in conscious pregnant sheep near term. In fetal-to-maternal studies, radiolabeled bile salt was injected into the fetal portal vein, and the daily excretion of radiolabel in maternal hepatic bile was measured over 3-4 days. In maternal-to-fetal studies, the mother received daily injections of radiolabeled bile salt, and the accumulation of label in the fetal pool was measured after 6-9 days. Bile salts were transferred predominantly as the taurine conjugate. Transfer rates were 1) fetus to mother; chenodeoxycholate, 6.7 mumol/24 h and deoxycholate, less than 0.5 mumol/24 h and deoxycholate, 1.4 mumol/24 h. We conclude that, in sheep near term, deoxycholate derived from the mother slowly accumulates in the fetus, while the placenta acts as an excretory route for fetal chenodeoxycholate.
D000818:Animals; D001692:Biological Transport; D002635:Chenodeoxycholic Acid / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000378:metabolism*; D005260:Female; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012756:Sheep / Q000196:embryology / Q000378:metabolism*
D003840:Deoxycholic Acid; D002635:Chenodeoxycholic Acid