Abstract: Objective To investigate the different dosages of cyclophosphamide (CY) and endpoint-detection on the effects of immunosuppression model. Methods BALB/c mice were divided into 4 groups randomly: negtive control group (A), CY 40 mg/kg group (B), CY 60 mg/kg group (C), which were all tested at 5 days after the last administration, and CY 60 mg/kg group-2 (D) was tested at 3 days after. The animal’s body weight was measured every day, hematological parameters and immune organ index were detected when the experiments finished, as well as immune function was mediated by T or B lymphocytes testing. Results The different doses of CY and endpoint-detection have impact on the immunosurpression effect. 60 mg/kg CY has stronger immunosurpression effect when tested at 5 days after the last administration. The alteration of immune indicators were more obervious when tested at 3 days after the last administration compared with 5 days at the dosage of 60 mg/kg CY. Conclusion Dosages of CY and endpoint-detection have impact on immunosuppressed mice model. 60 mg/kg CY is more effective than 40 mg/kg CY, and the results are better when 3 days after the last administration is chosen as the endpoint-detection.

Key words: Cyclophosphamide (CY), Endpoint-detection, Immunosuppression, Mice model