| Abstract: | Abstract: The antagonistic action of repeated administration of vitamin E and selenium on the lethality caused by a single intraperitoneal injection of doxorubicin 15 to 20 mg/kg has been investigated in mice. Mice were treated with vitamin E, 20 to 4100 mg/kg intraperitoneally/intramuscularly daily or once a week and/or selenium 27 μg/kg orally daily for 6 to 7 weeks, i.e. one or two weeks before and five weeks after doxorubicin administration. 30 mg/kg of doxorubicin intraperitoneally caused 100% lethality within 4 days, whereas 15 mg/kg caused no deaths within a week, but resulted in a delayed toxicity with a cumulative lethality of 80% at the end of the observation period of 6 months. Vitamin E protected the mice from the lethal effect of doxorubicin, 15 mg/kg during the administration, but the mice began to die when the vitamin E administration was discontinued. Selenium only protected the mice for two weeks in spite of the continuous administration of selenium. The combined administration of vitamin E and selenium had no protective effect on the lethality caused by doxorubicin, 20 mg/kg. The pathogenesis of the delayed lethality of a single doxorubicin administration in mice is discussed. It is concluded that vitamin E and/or selenium have no significant protective action against doxorubicin induced delayed lethality in mice. |
