RESPONSE OF HEPATIC-FUNCTION TO HEPATIC COPPER DEPOSITION IN RATS FEDA DIET CONTAINING COPPER

Fischer rats were a fed diet supplied with copper chloride (150-600 pp m) for 60 d from weaning. Serum (glutamic-oxaloacetic transaminase (GO T) and glutamic-pyruvic transaminase (GPT) activities were increased w ith the increase of Cu concentration in the diet. Biliary excretion of Cu was related to the dietary Cu level. Depositions of hepatic and re nal Cu were also related to the dietary Cu level in a dose-dependent m anner. In particular, hepatic (155.2 +/- 13.3 mu g/g) and renal (44.9 +/- 4.4 mu g/g) Cu concentrations increased abruptly in the Cu-600 ppm group. In the liver, about 60% of Cu was distributed in the soluble f raction (100,000 g supernatant). In the Cu-600 ppm group, 25% of cysto solic Cu was bound to metallothionein (MT). Our results suggest that c hronic exposure to Cu appears to have a deleterious effect on the hepa tic function, and further, that even in rats with normal biliary Cu ex cretion, clearance of Cu from the liver may be marginal when dietary C u is near the 600-ppm level. Although Cu is an essential nutrient, an overload of Cu should be avoided.