HIGH COPPER AND IRON LEVELS AND EXPRESSION OF MN-SUPEROXIDE DISMUTASEIN MUTANT RATS DISPLAYING HEREDITARY HEPATITIS AND HEPATOMA (LEC RATS)

The LEC rat is a mutant strain displaying hereditary hepatitis and hep atoma. We established enzyme-linked immunosorbent assays of Cu,Zn- and Mn-superoxide dismutase (Cu,Zn- and Mn-SOD) and measured the levels o f both SODs in various organs of LEC and Wistar rats. Mn-SOD concentra tions were higher in LEC rats than in Wistar rats in most tissues. Cu, Zn-SOD levels of liver, kidney and intestine were lower in LEC rats th an in Wistar rats. Atomic absorbtion techniques indicated that in addi tion to high Cu concentrations as previously reported, LEC rat livers contained high Fe concentrations relative to those in Wistar rat liver s. These data suggest that increased concentrations of Fe and Cu and d ecreased levels of Cu,Zn-SOD may facilitate the Fenton reaction to pro duce hydroxyl radicals in the tissues of the LEC rat. To compensate fo r the decreased scavenging effects due to low levels of Cu,Zn-SOD, an adaptive increase of Mn-SOD may occur in the process of hepatitis and hepatocarcinogenesis in LEC rats.