EFFECT OF DEHYDROCHOLIC, CHENODEOXYCHOLIC, AND TAUROCHOLIC ACIDS ON THE EXCRETION OF BILIRUBIN

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  • 1 January 1980
    • journal article
    • research article
    • Vol. 41  (3) , 355-361
Abstract
The effects of i.v. bile acid infusion (at .apprx. 20% of normal excretion rate) on the biliary excretion of 3-.alpha.-hydroxy bile acids and bilirubin were studied in ponies prepared surgically with chronic external biliary fustulas. Endogenous bile acid excretion (.apprx. 45 .mu.mol/min) decreased to the hepatic synthesis rate (.apprx. 1.5 .mu.mol/min) during the initial 4-5 h of bile drainage. In type 1 studies, both chenodeoxycholic and taurocholic acid infusion (8-9 .mu.mol/min) increased bilirubin excretion by 58-82% after 5 h of biliary diversion. During type 2 studies, 3 h i.v. infusions (10.5 .mu.mol/min) of dehydrocholic acid 4 h after biliary diversion increased bile flow by 45-62% and excretion of 3-.alpha.-hydroxy bile acid by 34-36% above preinfusion (hepatic synthesis) levels. Bilirubin excretion was not significantly changed during those increases in bile flow and bile acid excretion. Immediately after dehydrocholic acid infusion, taurocholic acid infusion (8.1 .mu.mol/min) greatly increased bilirubin excretion for 1 h (a reversal of hepatic storage identical to that found during type 1 studies), prolonged excretion (mg/2 h) being 2-3 times that caused by dehydrocholic acid infusion. Bilirubin excretion appeared to correlate with the micelle-forming capacity of endogenous bile acids as opposed to the nonmicelle-forming characteristic of synthetic dehydrocholic acid.