Changes in hepatic copper distribution leading to hepatitis in LEC rats.

Abstract

Copper (Cu) accumulating in the liver of LEC (Long-Evans with a cinnamon-like coat color) rats due to a hereditary metabolic disorder is assumed to cause acute hepatitis with severe jaundice or chronic hepatitis leading to cancer. Changes in concentrations and distributions of Cu, zinc and iron in the liver of LEC rats were determined to find the relationship between the chemical forms and the toxicity. Female rats after delivery were used because of high susceptibility to acute hepatitis. They were divided into four stages according to the development of jaundice. Cu concentrations in the whole liver and the supernatant decreased with development of jaundice. Distribution profiles of Cu, zinc, iron and sulfur on a gel filtration column by HPLC-ICP showed that Cu in the liver supernatant was mostly bound to metallothionein (MT) before jaundice (stage 1), high molecular weight proteins and MT at the beginning of jaundice (stages 2 and 3), and then mostly to MT at severe jaundice (stage 4) though the concentration of Cu at this stage was decreased to about 50% of stage 1. The results suggest that Cu accumulating as MT in the liver is liberated drastically after exceeding the capacity of MT synthesis, and the liberated Cu causes acute hepatitis.