Improvement of mitomycin C- and cyclophosphamide-induced thrombocytopenia and leucocytopenia by prior treatment with deoxyspergualin in dogs.

Deoxyspergualin (DGS) is a new immunosuppressant which has shown inhibitory haemopoietic activity. We investigated the myeloprotective effect of DSG against the haemopoietic injury of mitomycin C (MMC) or cyclophosphamide (CYC) by measuring peripheral blood cell numbers in dogs. DSG given at 5 mg/kg on days 3, 2 and 1 before, or at 10 mg/kg on either days 2 and 1 before or on day 1 before and the day of injection of MMC at 0.25 mg/kg ameliorated both the thrombocytopenia and leucopenia caused by MMC. This ameliorative effect was more evident on platelet counts than on white blood cell counts. In addition, the leucopenia and thrombocytopenia induced by a single injection of CYC at 10 mg/kg was also ameliorated by prior DSG administration. These findings suggest that DSG may be useful in protecting against the haemopoietic damage induced by chemotherapeutic agents in the treatment of cancer.