转人乳铁蛋白基因牛奶粉致突变性

Mutagenicity of recombinant human lactoferrin transgenic bovine milk powder

目的观察转人乳铁蛋白基因牛奶粉(LF)有无致突变效应。方法将40只雄性昆明小鼠随机分为8组,以2 500、5 000、10 000 mg/kg的转人乳铁蛋白基因牛奶粉(LF)连续灌胃5 d,以同等剂量的普通奶粉(荷斯坦奶牛)为亲本对照,并设阴性对照组和阳性对照组。于小鼠首次染毒后第35天观察精子畸形率。将80只昆明种小鼠按上述剂量及分组方法分为8组。间隔24 h两次给小鼠经口灌胃,观察骨髓嗜多染红细胞微核率。采用鼠伤寒沙门菌组氨酸缺陷型TA97、TA98、TA100、TA102四株试验菌株,LF设0.2、0.5、1.0、2.5、5.0 mg/皿5个剂量,以同等剂量的普通奶粉(荷斯坦奶牛)为亲本对照,并设阴性对照组和阳性对照组,采取非代谢活化和代谢活化(加S9)两种方式进行Ames试验。结果转人乳铁蛋白基因牛奶粉(LF)小鼠精子畸形试验、小鼠骨髓细胞微核试验、Ames试验结果均为阴性。结论在本试验条件下未见转人乳铁蛋白基因牛奶粉(LF)有致突变效应。

Objective To observe the mutagenetic effects of recombinant human lactoferrin transgenic bovine milk powder （LF）. Methods LF was administered to mate KM mice by gavage for five consecutive days at the doses of 2 500, 5 000 and 10 000 mg/kg body weight. Holstein milk powder was parent control, and one solvent control group（negative control group）, one positive control group were established at the same time. The teratospermia was observed at the 35th day after the first treatment. LF was administered by gavage twice at 24 h intervals at the doses of 2 500, 5 000 and 10 000 mg/kg body weight to mice, the control groups were treated as the same as the sperm malformation test. The micronucleus of bone marrow polychromatic erythrocytes was observed at the 6th hour after the first treatment. Histidine-defective strains of Salmonella typhimurium （TA97, TA98, TA100, TA102） were used, LF were mixed with 0.2, 0.5, 1.0, 2.5, 5.0 mg per vessel. Holstein milk powder was used as the parent control at the same dose, and one solvent control group （negative control group）, one positive control group were were established at the same time. The vessels were cultivated tbr 48 h at 37 ~C with $9 or without $9, number of revertant colonies was counted. Results Mice sperm malformation tests, Ames tests and bone marrow cell micronucleus tests were negative. Conchlsion No mutagenetic effects of recombinant human lactoferrin transgenic bovine milk powder were observed in the present study.