Synchronisation in vivo: temporary inhibition of DNA synthesis in the rat embryo with hydroxyurea

Abstract

As part of experimental studies on the synchronisation of mammalian cell populations in vivo, the proliferative response of rat embryo cells (18th day of gestation) was investigated following transplacental administration of hydroxyurea (HU). DNA synthesis was strongly inhibited by i.p. injection of a single dose of 0.25 or 0.5 mg HU/g body weight, for periods of 2.5 and 4.5 h, respectively. Reversal of blocks occurred rapidly due to the short half-life (45 min) of the inhibitor in the embryo. The resulting synchronizing effects were analysed in terms of mitotic indices and rate of 3H-TdR incorporation for a period of 18 h after administration of HU.