Incorporation of Deoxycytidine in DNA of the Lymphocytoid Cells of the Rat

Abstract

It has been established that ³H-thymidine inadequately labels the various lymphocytoid populations of the rat. Recently, ³H-deoxycytidine was shown to label these cells more adequately. The purpose of the present work was to verify if, as ³H-thymidine, ³H-deoxycytidine is incorporated only during the first 45 minutes following its injection. Rats were sacrificed at various intervals, up to 24 hours, after receiving an intravenous dose of one or the other DNA precursors. Radioautographs of their lymphoid organs revealed that, unlike ³H-thymidine, the incorporation of ³H-deoxycytidine continues during 24 hours after injection.