WADA, M.; OTSUKA, R.; SAKAMOTO, T.; ITO, M.; Tokyo Med. Dent. Univ., Chiba; Tokyo Med. Dent. Univ., Chiba; Transgenic, Inc., Kumamoto; Transgenic, Inc., Kumamoto: Effects of dietary administrated estradiol on reproducitive

To establish a method for administrating endocrine disruptor chemicals through diet, estradiol-17&b was mixed with powdered quail feed at the concentrations of 0.01, 0.1, 1, 10, 100, 1000 ppm and given to sexually matured male Japanese quail for a week in one group and 4 weeks in the other group. Average food consumption was constant at about 15 g/day for each bird of all the group except in the birds given highest dosage. Circulating vitellogenin significantly increased after a week in the group served with estradiol 1ppm mixed diet and the groups with higher concentrations. Combined testicular weight and the area of the cloacal protrusion decreased significantly in the birds given the highest dose of estradiol but those of the other birds given lower dosages were not different from control birds. The four week experiment indicated that 2 weeks were required to attain the plateau in the lower dose groups. The highest dosage, i.e. 1000 ppm, was rather toxic and survival rate was 33.3 % by the end of the 4 week experiment. To assess an effect of phytoestrogens on vitellogenin assay, phytoestrogen low diet was used to compare with normal diet which contain dizein, genistein and so on. The results indicated that these phytoestrogens did not induce circulating vitellogenin at the concentrations contained in the feed made of soybean and alfalfa as raw materials.