• 1 April 1986
    • journal article
    • research article
    • Vol. 46  (4) , 1581-1584
Abstract
The factors associated with the recovery of DNA synthesis in Chinese hamster ovary cells after inhibition with 9-.beta.-D-arabinofuranosyladenine have been investigated. Maintenance of cellular concentrations of the active metabolite 9-.beta.-D-arabinofuranosyladenine 5''-triphosphate was dependent upon a constant exogenous source of 9-.beta.-D-arabinofuranosyladenine, without which the triphosphate rapidly degraded. DNA synthesis was inhibited maximally at cellular concentrations of 9-.beta.-D-arabinofuranosyladenine 5''-triphosphate in excess of 100 .mu.M, but it recovered substantially as the triphosphate concentrations declined below 30 .mu.M. Autoradiographic studies indicated that 9-.beta.-D-arabinofuranosyladenine had a synchronizing effect on the cells and that recovery of DNA synthesis occurred initially at rates much reduced from those seen in uninhibited cells. A greater portion of an inhibited population recovered DNA synthesis than was able to retain clonogenic potential. These results are consistent with a mechanism of toxicity that postulates recovery of DNA synthesis as a requisite for the loss of viability.