Excessive accumulation of hepatic copper in LEC rats aged 80 days without hepatitis and 130 days with hepatitis.

The Cu concentration was about 40 and 60 times higher in the liver in Long-Evans with a cinnamon-like coat color (LEC) rats aged 80 days (without hepatitis) and 130 days (with hepatitis), respectively than in the liver in Fischer rats. Most hepatic Cu was recovered in the cytosol fraction. Furthermore, about 96% and 84% of the cytosolic Cu was found in the metallothionein region on a Sephadex G-75 column in LEC rats aged 80 and 130 days, respectively. The hepatic metallothionein concentration was about 130 to 140 times higher in LEC rats than in Fischer rats when the concentration was expressed as metallothionein-bound Cu. Three forms of Cu-metallothionein were isolated by DEAE-cartridge. Although the concentration of hepatic Cu-metallothionein and its composition of polymorphic form were not changed greatly in hepatitis phase (in the 130-day-old LEC rats), activities of serum enzymes, aspartate aminotransferase (GOT) and alanine aminotransferase (GPT) were increased significantly. The LEC rat showed a significantly low concentration of biliary Cu and markedly low activity of ceruloplasmin (as ferroxidase). Serum Cu showed a low concentration in the 80-day-old LEC rats, but recovered to the control level in the 130-day-old LEC rats. The abnormal accumulation of Cu may be due to the inherent reduction of excretion of Cu into the bile and blood. Such deposition may be a trigger for the onset of the spontaneous hepatitis occurring at 90-120 days after birth and for the onset of hepatoma later.