Influence of high levels of DDT in the diet on liver microsomal estrogen metabolism in the laying hen.

Two experiments were conducted with laying hens to evaluate the effect of technical grade DDT on estrogen metabolism by liver microsomes using an assay which measured the metabolism of estradiol-17beta-4-14C. In Experiment I feeding 500 ppm DDT in the diet had no significant effect on estrogen metabolism after 10 days. However, the metabolism was increased after 18 days and more than doubled after 51 days. In Experiment II hens were fed diets containing 0, 300, 600 or 1200 ppm DDT and estrogen metabolism by liver microsomes was examined at 0, 7, 14, 21 and 35 days. A significant increase in estrogen metabolism was seen at 14 days with the feeding of 600 or 1200 ppm DDT and at 21 days with 300 ppm DDT. The ability to metabolize estrogen reached a maximum increase of approximately two-fold in all hens fed DDT. This required 14 days when the birds were fed 1200 ppm DDT, 21 days when fed 600 ppm DDT and 35 days when fed 300 ppm DDT. The increase in estrogen metabolism caused by DDT was found to be dose and time dependent.