Action of polyamines on ribonucleic acid and protein synthesis during ontogeny of human fetal liver

Effect of ornithine on transferrin secretion of rat and human hepatocyte cultures

Fetal rat or neonatal human hepatocytes and a human hepatoma cell line were cultured in an arginine-free medium, supplemented or not with L-ornithine. This amino-acid improved survival of hepatocytes and strongly enhanced their transferrin secretion. Moreover, this increase observed in transferrin production was well correlated with a higher corresponding mRNA level. Thus, it may be postulated that the mechanism involved in the increased transferrin secretion by L-ornithine is of pretranslational origin.

Influence of ornithine on albumin synthesis by fetal and neonatal hepatocytes maintained in culture

Fetal rat as well as fetal and neonatal human hepatocytes were cultured in an arginine-free medium with or without L-ornithine. This amino acid was found greatly to improve cell survival of both rat and human parenchymal cells and to favour their proliferation. In addition, L-ornithine appeared to modulate the expression of various functions and particularly to increase albumin secretion. Since a correlated increase of the corresponding mRNA was observed, it may be postulated that L-ornithine acts at a pre-translational level.