Differential effect of procaine on irradiated mammalian cells in culture

HeLa and V-79 Chinese hamster cells temporarily stored in ampoules were treated with the local anesthetic procaine. Postirradiation treatment increased lethality in HeLa cells depending on drug concentration, duration of treatment and cell density, as measured by colony-forming ability upon plating. If present during irradiation only, procaine protected from irradiation. In V-79 cells procaine potentiated radiation lethality only in freshly trypsinized cells. Procaine effect was thus cell type specific and most likely involved the cell membrane.