The BrdU content of DNA is decreased during reversal of inhibition of myogenesis by deoxycytidine.
The mechanism by which 5-bromodeoxyuridine (BrdU) inhibits cell differentiation is unresolved. The ability of deoxycytidine to reverse the inhibition of myogenesis produced by BrdU has been cited as evidence that the inhibition is not a direct result of the incorporation of BrdU into cellular DNA. In contrast to previous work, the present study demonstrates a direct correlation between the effects of deoxycytidine on myogenic cells and a reduction in the substitution of BrdU for thymidine in the DNA. Further-more, the reversal occurs at the same degree of BrdU substitution (20-30%) as is required to inhibit myogenesis when cells are grown in BrdU alone or with deoxycytidine in a medium that prevents the conversion of deoxycytidine to thymidine. The effects of deoxycytidine thus do not support a mechanism of action of BrdU in myogenic cells independent of its effects on DNA.
D000818:Animals; D001973:Bromodeoxyuridine / Q000032:analysis* / Q000037:antagonists & inhibitors; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D002642:Chick Embryo; D004247:DNA / Q000032:analysis*; D003841:Deoxycytidine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D009132:Muscles / Q000166:cytology* / Q000378:metabolism; D051381:Rats
D003841:Deoxycytidine; D004247:DNA; D001973:Bromodeoxyuridine