Enhanced amino acid transport in cultured hepatocytes during liver development

Hepatocytes from neo- and postnatal rats were successfully isolated, purified from non-hepatocytes (erythropoietic cells), and cultured in sufficient amounts to perform transport kinetics of nutrients. In the presence of sodium (Na+-dependent component) the amino acid uptake measured with alpha-amino [1-14C]isobutyrate (AIB) as a tracer was markedly enhanced during early postnatal phases. Kinetic analyses of these enhanced velocity data revealed the presence of a low-Km transport system in the range of amino acid concentration in which AIB mimics physiological properties. The system provides neonatal hepatocytes with a great potential for concentrating amino acids during the early postnatal stage, and may have considerable effect on membrane linked regulatory processes during liver development.