Effects of oestradiol-17 beta and diethylstilboestrol on progesterone-induced protein (avidin) production in chick oviduct: evidence for differences in the actions of steroidal and non-steroidal oestrogens.

The effects of diethylstilboestrol (DES) and oestradiol-17 beta on the production of a progesterone-induced protein (avidin) in the chick oviduct were studied. Chicks were pretreated with DES or oestradiol-17 beta daily for 3-28 days and progesterone (10 or 20 mg/kg) was administered 24 h after the last oestrogen injection. Diethylstilboestrol (2-20 mg/kg) administered with progesterone to chicks pretreated with DES increased avidin production after 16 h compared with that induced by progesterone alone. The potentiation of avidin production appeared even when DES was administered between 6 h before and 13 h after progesterone injection. The length of DES pretreatment did not affect the potentiation. The amount of avidin induced by progesterone in the chicks pretreated with oestradiol-17 beta was similar to that in the chicks pretreated with DES. Oestradiol-17 beta (2-20 mg/kg) administered with progesterone, however, did not affect avidin production. The results suggest that DES may have some non-oestrogenic effects on the production of progesterone-induced proteins.