Decrease in biliary excretion of copper in Long-Evans cinnamon (LEC) rats causing spontaneous hepatitis due to a gross accumulation of hepatic copper

Abstract

The concentration of biliary Cu was 0.12 +/- 0.01 microgram/ml in male LEC rats aged 14 weeks and 0.43 +/- 0.09 micrograms/ml in Fischer rats of the same age. When copper chloride (170 micrograms/kg b.w. as Cu) was infused intravenously (i.v.), the concentration of biliary Cu increased to only 0.21 +/- 0.06 microgram/ml 30 min after the infusion in LEC rats. In contrast, Fischer rats showed a concentration about 10 times higher (4.02 +/- 2.2 micrograms/ml) than that before the infusion. In Fischer rats pretreated with cadmium chloride, the biliary Cu concentration was 1.04 + 0.43 micrograms/ml 30 min after infusion of copper. Horseradish peroxidase (E.C.1.11.1.7) infused iv along with copper chloride was excreted into bile at a low level in LEC rats compared to Fischer rats. Our results suggest that the gross accumulation of hepatic Cu in the new, mutant LEC rats is due to a low excretion of Cu into bile and that the hepatobiliary dysfunction is related to spontaneous hepatitis.