大鼠繁殖实验评价牛奶对生殖发育的影响

目的观察牛奶和高剂量大豆异黄酮(SI,1g/kg)对亲代大鼠生殖能力和F1代仔鼠发育状况的影响,以评价牛奶的安全性。方法选择交配前期、宫内暴露期、哺乳期和仔鼠性成熟期(受孕前11周至仔鼠35天性成熟)分别饲喂某品牌全脂牛奶及含高剂量SI的饲料,观察亲代体重、形态学、生殖能力、生殖器官、激素水平和F1子代发育状况的变化。使用SPSS13.0统计分析,均数比较采用方差分析的统计方法。结果牛奶和高剂量的SI对亲代的动情周期、交配指数、繁殖力指数、怀孕指数、孕周、每窝活产数、子代性别比、出生身长、4日生存率均没有影响。但是牛奶组仔鼠出生体重显著增加,亲代雄鼠血液中的促黄体生成素(LH)显著降低,雌鼠血液中孕酮显著低于空白组(P<0.05);植物雌激素SI组亲代雄鼠血液中卵泡刺激素(FSH)显著降低,雌鼠血液中孕酮和催乳素(PRL)显著低于空白组(P<0.05)。牛奶和高剂量SI对F1代仔鼠只数、性别比、肛门生殖孔间距体重比、阴道开口时间和包皮分离时间均没有显著影响。结论一代繁殖实验未发现牛奶对生殖能力和子代发育能力有显著影响,但亲代大鼠血液中激素水平有所改变,其是否影响子代大鼠二代繁殖能力,需进一步实验验证。

Safety assessment of Milk on reproductive development by reproduction study

Objective Observe the influence of whole fat milk and high-dose soy isoflavones(SI,1g/kg) on reproductive development to assess the safety of milk.Methods Sixty Spraque-Dawley rats(30 male and 30 female) were randomly separated into milk group,SI group and control group(10 male and female each) according to body weight and were fed with milk,the diet with 1g/kg SI and basic diet,respectively.Intervention measures were implemented from 11 weeks before mating to sexual maturity of F1.Parental weight,morphology,reproductive capacity,reproductive organ function,the level of hormones of parental rats and the development status of the first filial generation rats were examined.ANOVA were used to assess differences in groups with SPSS 13.0 statistical software;P<0.05 were considered statistically significant.Results The birth weight of F1 offspring in milk group was significantly increased(P<0.05).The level of luteinizing hormone(LH) of male rats and progesterone(P)of female rats in milk group were lower than those of control group(P<0.05).SI group vs control group significantly decreased P and PRL in female rats of the P generation(P<0.05).And The level of FSH in male rats of the P generation was lower than that of control group(P<0.05).There was no significant differences on the other indices such as estrous cycle,mating index,fertility index,pregnant index,gestation length,Number of pups,sex ratio,anogenital distance,vaginal opening(VO),preputial separation(PPS) in milk group and SI group,compared with control group.Conclusion Milk did not show significant influence on the reproductive development ability in the one-generation reproduction study.Further study is required to determine whether milk have adverse effects on reproductive health for F2-generation.