Abstract: Objective To investigate the abundance of metabolic proteins in adult and fetal human livers. Methods Adult liver
homogenate proteins, fetal liver homogenate proteins, adult liver mitochondrial proteins and fetal liver mitochondrial proteins
were obtained from fetal or adult liver tissues and examined using the antibody microarrays containing 19 liver monoclonal
mitochondrial antibodies. The protein expression abundances were compared among the 4 protein fractions and the pathways
related to protein metabolisms were explored. Results In adult liver mitochondria, aldehyde oxidase and carbonyl reductase
were up-regulated by 2.6 and 1.7 folds, respectively, whereas corticosteroid 11-beta-dehydrogenase isozyme 1, epoxide
hydrolase 1 and fibrinogen beta chain protein were down-regulated by 1.7, 1.9 and 2.2 folds, respectively, compared to those in
fetal liver mitochondria. The abundance of epoxide hydrolase 1 and glutathione transferase omega-1 was significantly
different between adult and fetal liver homogenate samples. Conclusion Our results demonstrate a clear difference in the
expression profiles of metabolic proteins in the liver between adults and human fetuses to allow a better understanding of the
occurrence and development of the metabolic proteins and the identification of markers of liver metabolism.