Cytidine uptake and utilization in primary culture from the rat brain

The uptake of labelled cytidine from primary cell cultures from rat embryo brain has been studied. A preferential flow of the cytosine moiety towards CDP-choline is evident. Labelled uracyl derivatives represent only a small fraction of the radioactivity measured in the hydrosoluble fraction of the cell extract, at any incubation time. CDP-choline synthesized from labelled cytidine belongs to the metabolic pool implicated in phospholipid synthesis. The evidence for the uptake of the intact cytidine molecule is also given.