Objective Environmental estrogens at an elevated concentration are known to produce adverse effects on human and animal life. However, the majority of researches have been focused on industrial discharges, while the i...Objective Environmental estrogens at an elevated concentration are known to produce adverse effects on human and animal life. However, the majority of researches have been focused on industrial discharges, while the impact of livestock wastes as a source of endocrine disrupters in aquatic environments has been rarely elucidated. In order to investigate the contribution of environmental estrogens from livestock, the estrogenic activity in water samples from a farm wastewater treatment plant was analyzed by a recombinant yeast screening method. Methods The extracts prepared from 15 selected water samples from the farm wastewater treatment plant, among which 6 samples were from pre-treatment section （influents） and 9 from post-treatment section （effluents）, were analyzed for estrogenic activity by cellar bioassay. Yeast cells transfected with the expression plasmid of human estrogen receptor and the Lac Z reporter plasmid encoding β-galactossidase, were used to measure the estrogen-like compounds in the farm wastewater treatment plant. Results The wastewater samples from influents showed a higher estrogenic potency than the effluent samples showing a low induction of β-galactossidase relative to solvent control condition. By comparison with a standard curve for 17β-estradiol （E2）, estrogenic potency in water samples from the influents was calculated as E2-equivalent and ranged from 0.1 to 150 pM E2-equivalent. The estrogenic potency in water samples from the effluents was significantly lower than that in the influents, and 7 water samples had less detectable limit in the total of 9 samples. Conclusion Yeast bioassay of estrogenic activity in most of the samples from the farm wastewater after disposal by traditional sewage treatment showed negative results.展开更多
To study the effect of endocrine disruptor chemicals in cow milk on female reproductive system. Methods A two-generation reproduction was conducted according to U. S. FDA standard. Milk was fed in special bottle to Wi...To study the effect of endocrine disruptor chemicals in cow milk on female reproductive system. Methods A two-generation reproduction was conducted according to U. S. FDA standard. Milk was fed in special bottle to Wistar rats of both sexes through two successive generations （F0 and F1） in the milk group while artificial milk was fed to rats in the control group. Twenty-four rats of each sex were mated in each group. Measurements were made according to this guideline. Results Reproductive parameters in the milk group such as fertility index, gestation index, weights of uterus and ovary, days of vaginal opening, estrous cycles, histological morphological changes were comparable to those in the control group. However, the means of body weight had some differences. The body weight gains increased significantly in the milk-treated group in F1 and F2 generation compared with those in the control group. The concentration of insulin-like growth factor-1 （IGF-1） in blood in the milk group was comparable to that in the control group, but the standard deviation changed greatly in the milk-treated rats. Conclusion Endocrine disruptor chemicals in milk have no severe effects on the female reproductive system.展开更多
基金the Natural Science foundation of Jiangsu Education Bureau (03KJB610168)
文摘Objective Environmental estrogens at an elevated concentration are known to produce adverse effects on human and animal life. However, the majority of researches have been focused on industrial discharges, while the impact of livestock wastes as a source of endocrine disrupters in aquatic environments has been rarely elucidated. In order to investigate the contribution of environmental estrogens from livestock, the estrogenic activity in water samples from a farm wastewater treatment plant was analyzed by a recombinant yeast screening method. Methods The extracts prepared from 15 selected water samples from the farm wastewater treatment plant, among which 6 samples were from pre-treatment section （influents） and 9 from post-treatment section （effluents）, were analyzed for estrogenic activity by cellar bioassay. Yeast cells transfected with the expression plasmid of human estrogen receptor and the Lac Z reporter plasmid encoding β-galactossidase, were used to measure the estrogen-like compounds in the farm wastewater treatment plant. Results The wastewater samples from influents showed a higher estrogenic potency than the effluent samples showing a low induction of β-galactossidase relative to solvent control condition. By comparison with a standard curve for 17β-estradiol （E2）, estrogenic potency in water samples from the influents was calculated as E2-equivalent and ranged from 0.1 to 150 pM E2-equivalent. The estrogenic potency in water samples from the effluents was significantly lower than that in the influents, and 7 water samples had less detectable limit in the total of 9 samples. Conclusion Yeast bioassay of estrogenic activity in most of the samples from the farm wastewater after disposal by traditional sewage treatment showed negative results.
文摘To study the effect of endocrine disruptor chemicals in cow milk on female reproductive system. Methods A two-generation reproduction was conducted according to U. S. FDA standard. Milk was fed in special bottle to Wistar rats of both sexes through two successive generations （F0 and F1） in the milk group while artificial milk was fed to rats in the control group. Twenty-four rats of each sex were mated in each group. Measurements were made according to this guideline. Results Reproductive parameters in the milk group such as fertility index, gestation index, weights of uterus and ovary, days of vaginal opening, estrous cycles, histological morphological changes were comparable to those in the control group. However, the means of body weight had some differences. The body weight gains increased significantly in the milk-treated group in F1 and F2 generation compared with those in the control group. The concentration of insulin-like growth factor-1 （IGF-1） in blood in the milk group was comparable to that in the control group, but the standard deviation changed greatly in the milk-treated rats. Conclusion Endocrine disruptor chemicals in milk have no severe effects on the female reproductive system.
