VARIATIONS IN PEROXISOMAL CATALASE OF NEONATAL RAT HEPATOCYTE SUBPOPULATIONS - EFFECT OF PRENATAL AND POSTNATAL EXPOSURE TO ALCOHOL

Alcohol consumption during pregnancy is teratogenic and induces severe alterations in hepatocytes. In the hepatocyte peroxisomal system, eth anol is converted in the presence of H2O2 to acetaldehyde and wa ter. Therefore, peroxisomal catalase also acts as an antioxidant defence me chanism by removing H2O2 and preventing the formation of hydroxyl radi cals in the cell. Alterations in peroxisomal catalase after pre- and p re+postnatal alcohol exposure were investigated in the rat. The effect of pre- and postnatal exposure to ethanol on hepatocyte subpopulation s was analysed in isolated hepatocytes originating from periportal, in termediate and perivenous zones. Analysis of catalase revealed that th e total activity and content of this enzyme were higher in 12-day-old cells than in cells from newborns and that this increment was more pro nounced in treated cells. In controls, the amount of peroxisomal catal ase increased mainly in periportal cells, whereas alcohol exposure ind uced a significant increase in the catalase of perivenous hepatocytes. We conclude that pre- and postnatal alcohol exposure mainly affects t he perivenous hepatocyte peroxisomes and that the increase in peroxiso mal catalase could constitute a defence mechanism against free radical generation induced by alcohol exposure during the perinatal period.