Dopamine pretreatment in mice diminishes the hematotoxic effects of cyclophosphamide

An investigation was carried out to examine whether dopamine (DA) has any p rotective effect on anticancer drug-induced hematotoxicity. Normal Swiss mi ce were injected i.p. with 50 mg / kg body weight / day of DA for five cons ecutive days. After 24 hr of last DA injection, cyclophosphamide (CY) was i njected i.v. at a single dose of 200 mg / kg body wt. CY injection was foll owed by marked inhibition of total circulating leukocyte count, severe neut ropenia, bone marrow and splenic hypocellularity and profound diminution of granulocytic and erythroid cells in the bone marrow. DA treatment prior to CY injection elicited appreciable protection against these adverse effects of CY. For instance, leukopenia and neutropenia were of lesser magnitude a nd the nadir were observed on day 4 instead of day 2 in CY-only group. In a ddition, total WBC and neutrophil recovery were completed by day 6 after CY injection which was 72 hr earlier than the group which did not receive DA before CY. Cytological and cytochemical studies revealed reduction in the s everity of suppressive effect of CY on bone marrow granulocytes and their p rogenitors in mice pretreated with DA. Substantial increments in the number of megakaryocytes and erythroid cells were observed in the spleen of DA - treated animals. Thus, it is concluded that DA treatment before CY mediates appreciable reduction in the severity of hematotoxicity elicited by this c ancer chemotherapeutic agent.