OBJECTIVETo investigate effective doses of cyclophosphamide (CTX) for establishment of leukopenia model in ICR mouse.

METHODSNormal ICR mice (n = 96) were divided into CTX(80), CTX(100), CTX(120), CTX(150) and CTX(300) groups, of which mice received CTX intraperitoneally at a dose of 80, 100, 120, or 150 mg/kg once a day for 3 consecutive days, or 300 mg/kg with single injection. The peripheral blood cell counts were detected at various times before and after CTX administration.

RESULTSThe peripheral white blood cell nadirs in the mice injected with CTX appeared on day 4 after the first dose of CTX. The peripheral white blood cell nadir in group CTX(100) was 26.7% of the value measured in mice before CTX administrated, and that of group CTX(80) was 35.0%. Higher doses of CTX, however, caused too severity in hematopoietic injury.

CONCLUSIONThe dose of CTX 100 mg/(kg·d) × 3d is appropriate for leucopenia model of ICR mouse.