CHANGES IN BILE-ACID COMPOSITION OF SERUM AND GALLBLADDER BILE IN BILE-DUCT LIGATED DOGS

Biliary obstruction was produced by surgical ligation of the common bi le duct to observe alterations in serum bile acid composition. The per cent composition of serum bile acids was found to change with time. Ta urocholic acid increased on day 3 and accounted for More than 90% of t he total bile acids in all dogs, however it decreased after day 7. The percentage of taurochenodeoxycholic acid (TCDC) and taurodeoxycholic acid (TDC) decreased to 4.2-6.0% and 0.2-0.7% on day 3, respectively. However, the percentage of TCDC increased after day 7 in all dogs and reached greater than 20% on day 14 in 2 dogs, whereas the percent TDC after bile duct ligation remained low in all dogs. Glycolithocholic ac id, which was not identified in normal dog sera, was detected on day 3 and remained throughout the study in all dogs. Bile acid composition of gallbladder bile sampled on day 35 was similar to the serum bile ac id composition on the same day. This indicates that the bile acids ref luxed into the circulation in these dogs. In the present study, total cholic acid to chenodeoxycholic acid (C:CDC) ratio increased to 15.5-2 2.3 at three days post bile duct ligation and after the day 14, the C: CDC ratio decreased to its pre-ligation value or below. In contrast, t he glycine conjugated to taurine conjugated bile acids (G:T) ratio did not change. Therefore, at this time, the G:T ratio would not be usabl e as an indicator of liver disease in dogs while it may be possible to use the C:CDC ratio.