大鼠Pig-a基因突变试验中N-乙基-N-亚硝基脲和环磷酰胺量-效关系的优化

目的研究不同剂量的N-乙基-N-亚硝基脲(ENU)和环磷酰胺(CP)对SD大鼠外周血红细胞表面锚蛋白CD59缺失率的影响,优化Pig-a基因突变试验检测方法。方法将SD大鼠按体重和外周血RBCCD59-随机分为4组,即溶媒对照组,CP 40 mg/kg给药组,ENU 10 mg/kg给药组和ENU 40 mg/kg给药组,每组6只,腹腔染毒,溶媒对照组注射PBS溶液。在染毒前和染毒后7、14、21、28、42、56 d进行称重和采血,流式检测外周血RBCCD59-发生率。结果与溶媒对照组比较,ENU 10 mg/kg给药组和ENU 40 mg/kg给药组各时间点体重及体重增量差异均无显著性,CP 40 mg/kg给药组各时间点体重及体重增量均下降(P0.05)。CP 40 mg/kg给药组给药后第28、42和56天,ENU 10 mg/kg给药组给药后第42、56天,ENU 40 mg/kg给药组给药后第7、14、21、28、42和56天外周血RBCCD59-发生率均升高(P0.05),且具有剂量反应关系。结论在开展Pig-a基因突变试验中,ENU引起大鼠外周血RBCCD59-发生率升高效果优于CP,且40 mg/kg剂量优于10 mg/kg,检验周期28 d为宜。

Optimization of the dose-effect relationship of N-ethyl-N-nitrocarbamide and cyclophosphamide in Pig-a gene mutation detection in rats

Objective The effect of different doses of ethylnitrosourea (ENU) and cyclophosphamide (CP) on the loss rate of CD59 on peripheral blood erythrocytes was explored to optimize the detection method of Pig-a gene mutation. Methods According to the weight and loss rate of CD59 on peripheral blood erythrocytes, rats were divided into 4 groups: the control group, CP 40 mg/ kg group, ENU 10 mg/ kg group and ENU 40 mg/ kg group (n =6). The control group was injected i. p. with PBS, other groups were injected i. p. with corresponding solutions. The body weight of rats on days 0, 7, 14, 21, 28, 42 and 56 were recorded. At the same time, blood samples were collected and incubated with antibodies, and the loss rate of RBC ^CD59- was detected by flow cytometry. Results Compared with the control group, at different time points, the body weight and weight gain of ENU 10 mg/ kg group and ENU 40 mg/ kg group had no statistically significant difference (P > 0.05), while those in the CP 40 mg/ kg group were significantly decreased (P <0.05). The loss rate of RBC ^CD59- was significantly increased in the CP 40 mg/ kg group at 28, 42 and 56 days, ENU 10 mg/ kg group at 42 and 56 days, and ENU 40 mg/ kg group at 7, 14, 21, 28, 42 and 56 days, (P < 0.05). The results showed a dose-response relationship. Conclusions Under the conditions of this Pig-a mutation detection method , ENU is superior to CP on raising loss rate of RBC ^CD59- , ENU 40 mg/ kg is better than 10 mg/ kg, and 28 days is suitable as the test period.