Abstract
Uridine kinase activity in rat liver decreases during embryonic and postnatal development. Administration of 5-azacytidine enhances liver uridine kinase activity in adult rats, but depresses it in embryos. The liver enzymes from the foetus and the adult are precipitated at different (NH4)2SO4 concentrations although they are eluted at about the same position on chromatography on a column of Sepharose 6B.