Radiosensitization and radioprotection studies on Ehrlich ascites tumor. II. Experimental trial of lucanthone to enhance the radiosensitivity of the tumor.

Lucanthone (miracil D) is reported to be carcinostatic and a radiosensitizer. But in our study lucanthone alone (70 mg/kg body weight) had no lasting effect on the Ehrlich carcinoma in mice. Based on mitotic studies, 4-day old ascites tumor was not sensitized to X-rays when pretreated with lucanthone. Tumor growth, evaluated as the average weight of solid tumors or the number of tumor cells in ascites bearing mice, was not significantly different between the group treated with X-rays only and the one treated with lucanthone plus X-rays. Thus lucanthone seems to enhance the radiosensitivity of certain cell types but not of the tumor tested. The orobable mechanism of action of the drug leading in some cases to enhanced radiosensitivity is presented.