Inhibition of biological effects of bromodeoxyuridine by deoxycytidine: correlation with decreased incorporation of bromodeoxyuridine into DNA.

The effects of 5-bromodeoxyuridine (BrdU) on pigmentation, contact inhibition, cell morphology, and tumorogenicity of Syrian hamster melanoma cells are inhibited in the presence of deoxycytidine (dC). The inhibition of these biological effects of BrdU by dC is correlated with a decrease in the incorporation of BrdU into nuclear DNA. The results suggest that the intracellular changes resulting from the addition of dC to cells in the presence of BrdU are comparable to those resulting from a decrease in the concentration of BrdU in the medium.