EFFECTS OF APHIDICOLIN ON ENTAMOEBA-HISTOLYTICA GROWTH AND DNA-SYNTHESIS

We have previously demonstrated that DNA polymerase activity of Entamo eba histolytica is inhibited by aphidicolin, which is a specific inhib itor of eukaryotic nuclear replicative DNA polymerases. The present st udy was aimed to evaluate the effect of aphidicolin on growth and DNA synthesis by this parasite. Aphidicolin blocked the growth of axenic E . histolytica strain HM-1:IMSS. DNA synthesis was also inhibited by ap hidicolin when assayed by incorporation of [H-3]thymidine into the DNA . The inhibitory effect of aphidicolin on the growth of E. histolytica was abrogated by removal of the drug, and exposure to 3 mu g/ml of th e drug for at least 48 hr had little effect on the viability. Synchron ous growth was observed in the recovery phase after removal of aphidic olin.