卫生研究

目的比较用环磷酰胺(CTX)诱导正常小鼠免疫抑制的两种方法,选择合适的免疫抑制动物模型以评价保健食品的安全性。方法以环磷酰胺为受试物,设立正常对照组、CTX-1组和CTX-2组;正常对照组每日灌胃蒸馏水,CTX-1组每日灌胃60mg/kg环磷酰胺,CTX-2组于试验结束前一天腹腔注射200mg/kg环磷酰胺,试验周期为30天。观察不同剂量及不同方式给予环磷酰胺后对小鼠各项免疫指标的影响。结果CTX-1组小鼠体重、脾脏重量、外周血淋巴细胞计数、NK细胞活性、细胞毒性T细胞活性、HC50均低于对照组(P<0.05),CTX-2组小鼠外周血T淋巴细胞(%)、Th细胞(%)、Ts细胞(%)及Th/Ts比值较对照组增高(P<0.001,P<0.001,P<0.05,P<0.05,P<0.001),其它各项指标均较对照组降低(P<0.05)。结论灌胃给予60mg/kg环磷酰胺30天与一次性腹腔注射200mg/kg环磷酰胺均可建立小鼠免疫低下模型,但前者更适用于建立评价保健食品安全性的免疫低下模型。

Objective To compare the methods for developing immune-suppressed mice models induced by cyclophosphamide(CTX) with different dosages and ways.Methods The mice were assigned to three groups;distilled water were given by gavage daily to the mice in control group;60 mg /kg of CTX were given by gavage daily to the mice in CTX-1 group;and the mice in CTX-2 group were intraperitoneally injected(ip) with 200 mg /kg bw of CTX one day before the end of the experiment.The experiment lasted for 30 days.Results The body weight,spleen weight,the percentage of lymphocytes in peripheral blood,activities of natural killer cells(NK) and cytotoxic T lymphocytes(CTL) and HC50 in CTX-1 group were significantly lower than those in the control group(P < 0.05).The percentage of T lymphocytes in peripheral blood,the percentage of Th and Ts lymphocytes and Th /Ts ratio in CTX-2 group were significantly higher than those in the control group(P < 0.05).Other immunological indices in CTX-2 group were significantly lower than the control group(P < 0.05).Conclusion A proper immunosuppressed animal model for the functional food evaluating system could be established by gavaging 60 mg /kg bw of CTX for 30 days or by one intraperitoneal injection(ip) of 200 mg /kg.But the former might be more fitted to establish the immunosuppressed model.