[Testosterone and dihydrotestosterone radioimmunoassays in Müllerian ducts of control and testosterone propionate injected quail embryos (author's transl)].

Testosterone (T) and dihydrotestosterone (DHT) have been quantitated by means of radioimmunoassay in Müllerian ducts (CM) from control quail embryos (6 to 8-day male and 6 to 15-day female) and from female embryos injected with 50 nanograms of testosterone propionate (PT) on the 8th day. These hormones are demonstrable in undifferentiated CM from 6-day control embryos. In control males although a highly significant decrease of the CM weight occurs during the CM involution, the detected amounts of androgens remain at a constant level. In control females, the right CM shows a slight increase of the androgen content during the rudimentation, i.e. from day 8 on; in the left CM: the highest steroid levels are found on the 6th day; while the CM differentiate, concentrations decrease and become similar to those found in neutral tissues. Given testosterone propionate on day 8 female embryos: right CM: both testosterone and DHT levels highly increase until day 14; the CM of treated embryos contain 8 times as much steroid as control; left CM: testosterone and DHT increase after injection until day 9,5; they slightly decrease between days 9,5 and 12, and then remain constant on day 14. Differences in concentrations are highly significant between CM of control and of PT - injected embryos. It seems that the binding sites of these androgens are more numerous during the involution and that bound testosterone or DHT could take a part in CM regression in male embryos and right CM rudimentation in female embryos.