Heterogeneity of hepatic acetaldehyde adducts in guinea-pigs after chronic ethanol administration: An immunohistochemical analysis with monoclonal and polyclonal antibodies against acetaldehyde-modified protein epitopes

The formation of acetaldehyde (AcH) adducts was immunohistochemically demonstrated in the livers of experimental animals after chronic ethanol consumption. Recently, we established a hybridoma producing monoclonal antibody against the adduct. Although the polyclonal antibody obtained from a rabbit immunized with adducts had affinities for AcH adducts produced with 20 μM, 1 mM and 10 mM of AcH, the monoclonal antibody could recognize only those produced with 1 and 10 mM of AcH, suggesting that there is a difference of antigenecity between the adducts formed with a high concentration of AcH and those modified with a low concentration of AcH. AcH adducts in the liver of guinea-pigs fed ethanol for 90 days were detected by immunohistochemical staining with the polyclonal and monoclonal antibodies. The staining of liver specimens with polyclonal antibody was observed around both the portal and perivenular areas, whereas the reactions to monoclonal antibody were localized only in the perivenular area. These data suggest that AcH adducts are able to be formed around both portal and perivenular areas in the liver and that the perivenular area might be exposed to a higher concentration of AcH than the portal area after ethanol intake.