MODULATION OF MUSTARD TOXICITY BY TACRINE

Compounds containing the chloroethyl group are potent inhibitors of DN A synthesis and cell growth. Tacrine, a choline carrier inhibitor, was found to protect both HeLa cells and rat thymocytes against the effec ts of nitrogen mustard. DNA synthesis was restored from 13 to 71% of t he control value and cell viability restored from 27 to 57% of the con trol value by exposure of the cells to an equimolar concentration of t acrine immediately prior to nitrogen mustard. In contrast, tacrine was unable to significantly protect rat thymocytes against the toxic effe cts of sulphur mustard. These results have implications for the clinic al use of nitrogen mustard.