长期饮用牛奶对雄性大鼠生殖功能的影响

Effect of long-term milk-drinking on reproductive function of male rats

目的 通过2代繁殖实验研究长期饮用牛奶对雄性大鼠生殖功能的影响.方法 牛奶组及对照组4周龄SD大鼠,雌雄各20只.牛奶组饲喂牛奶组饲料和市售纯牛奶,对照组饲喂对照组饲料.实验开始10周后合笼,产下子一代（F1）和子二代（F2）后处死雄性大鼠,分别记录雄性大鼠生长发育情况、精子水平、激素水平、子代活产数等指标.结果 亲代牛奶组雄鼠血液中促黄体生成激素（LH）（0.43±0.17）U/L低于对照组（0.72±0.26）U/L,子二代F2b活产数对照组（17.00±2.94）只高于牛奶组（13.10±3.57）只,亲代牛奶组大鼠体重在第12周（476.62±38.70）g低于对照组（515.37±37.59）g,差异均有统计学意义;各器官的脏器系数、精子和生育相关指标在两代的两组间差异均无统计学意义.结论 未发现长期饮用牛奶对雄性大鼠生殖功能有明显影响,牛奶对亲、子代体内激素水平和子代活产数的作用有待进一步确认.

Objective To investigate the effect of long-term milk-drinking on male rat reproductive function of both the parent generation （P） and the first generation （F1）. Methods Forty four-week Spraque-Dawley rats （20 males and 20 females） were randomly divided into milk group and control group according to their body mass by table of random number, and were fed with the diet with milk and normal diet for two generations, respectively. Male rats were ma- ted with female rats at 10th week of intervention. Body weight, number of pups, blood hormone level, reproductive organ, anogenital distance, preputial separation （PPS） and sperm parameters were examined. One male and one female were ran- domly chosen from each litter as the F1 generation （total number = 20; 10 males and 10 females）. The procedure of F1 generation was the same as P generation. Results The LH concentration in the milk group （0.43± 0.17） U/L in P gen- eration was significantly lower than the controls （0.72 ± 0.26） U/L. In addition, the number of F2b in the milk group （ 17.00 ± 2.94） was significantly lower than the control group （ 13.10 ± 3.57 ）. Mean weight of the milk group of P gener- ation was significantly higher than the control group [ （476.62 ~ 38.70）g vs. （515.37 ＋ 37.59）g, respectively ]. There were no significant differences in other indices between the milk group and the control group. Conclusion Long-term milk-drinking did not show significant influence on the reproductive functioning in the two-generation reproduction study. Further study is needed to determine the effects on hormone and number of pups.