1. The authors investigated the effect of two
extrahepatic cholestasis models (one by bile duct
ligation and the other by choledocho-jugular
fistula) on the hepatic clearance of
horseradish peroxidase in male Sprague-Dawley rats divided into four groups. 2. In groups A (n = 5 rats) and B (n = 5), bile duct
ligation was performed, while a choledocho-jugular
fistula was created in groups C (n = 5) and D (n = 7).
A 10 mg intravenous bolus of
horseradish peroxidase was injected after 24 h (groups A and C), 48 h (groups B and D) or 1 h (Group E; five
sham-operated rats). Serum and bile samples were then serially collected for 2 h. 3. In all groups, serum
horseradish peroxidase levels increased soon after injection and then rapidly decreased, the curves being similar. Biliary excretion increased for 30 min and then slowly decreased. The highest
horseradish peroxidase biliary concentrations and outputs were found in Group B followed by Group A; both groups had significantly higher levels than Group E. No difference was found between
horseradish peroxidase biliary excretion of groups C and D and that of
sham-operated rats. 4. When each group was considered separately, sampling times correlated with the corresponding ratios of bile/plasma HRP. Significant differences were found between the relative slopes of groups A, B and E, but not between those of groups C, D and E. 5. In conclusion,
bile duct obstruction greatly affects the plasma-bile transfer of fluid phase markers, such as
horseradish peroxidase, while single retention, caused by choledocho-jugular
fistula, has no influence.(ABSTRACT TRUNCATED AT 250 WORDS)