Increased transport of (G-14C) cytidine into rat liver after administration of alpha-hexachlorocyclohexane.

The transport of cytidine into liver over a wide dose range (0.003--100mumol per animal) proceeds as an nonsaturabel process. After the administration of alpha-hexachlorocyclohexane (alpha-HCH)1 the transport of (G-14C) cytidine is markedly activated if the concentration of nucleoside administered is low; the differences between the control and experimental group disappear after the administration of higher doses of the nucleoside. The incorporation of (G-14C) cytidine into RNA cytosine is enhanced after the administration of alpha-HCH. The degree of utilization of labeled cytidine for the RNA synthesis decreases in proportion to the logarithm of its dose, both in the control and in the experimental group. Increased transport of (G-14C)cytidine is observable even between the 4th and 6th day after the administration of a single dose of alpha-HCH.