Immunoelectrophoretic analysis of 25-day-old newborn and adult rat livers verified the presence of a 6-arc pattern of catalase observed earlier for purified rat hepatic catalase and for liver homogenates. Application of the immunoelectrophoretic method to fetal and newborn liver homogenates revealed a gradual shift from predominantly anodic arcs present in the fetal and early newborn period to largely cathodic arcs present in the 14-day newborn animals, followed by a full complement of catalase subcomponents present in 25-day-old and adult livers. The pattern due to erythrocyte catalase subcomponents present in liver homogenates could be readily differentiated from the hepatic catalase pattern.
Quantitative assay of all liver homogenates showed a 4- to 5-fold increase in catalase activity during the 16- to 20-day fetal period and correlated with an increased concentration of a single subcomponent. Little alteration in enzyme activity occurred during the perinatal period. The mean value of hepatic catalase activities at 14 days was lower than the early newborn period and was accompanied by a shift in prominence of cathodic subcomponents associated with the absence of 2 anodic arcs seen in younger fetuses. The livers of 25-day newborn animals demonstrated adult levels of catalase activity and an adult-type pattern.
Supported in part by USPHS Grant No. CA 08596-01 and a grant from the California Institute for Cancer Research.