Interaction of Estrogen and Progesterone in Chick Oviduct Development

Abstract

Daily administration of estrogen to immature female chicks results in marked oviduct growth and appearance of characteristic tubular gland cells which contain lysozyme . Although a rapid increase in total DNA and RNA content begins within 24 hr, cell specific protein, lysozyme, is first detectable after 3 days of estrogen . Progesterone administered concomitantly with estrogen antagonizes the estrogen-induced tissue growth as well as appearance of tubular gland cells and their specific products, lysozyme and ovalbumin . When the initiation of progesterone administration is delayed for progressively longer periods (days) during estrogen treatment, proportionally greater growth occurs with more lysozyme and tubular gland cells after 5 days of total treatment. Progesterone does not inhibit the estrogen-stimulated increase in uptake of a-aminoisobutyric acid and water by oviduct occurring within 24 hr or the estrogen-induced increase in total lipid, phospholipid, and phosphoprotein content of serum . The above results of progesterone antagonism can best be explained by the hypothesis that progesterone inhibits the initial proliferation of cells which become tubular gland cells but does not antagonize the subsequent cytodifferentiation leading to the synthesis of lysozyme and ovalbumin once such cell proliferation has occurred .

Effect of Tamoxifen on Oestradiol and Progesterone‐Induced Synthesis of Ovalbumin and Conalbumin in Chick Oviduct

“…After injection of oestradiol benzoate, the first significant increase in ovalbumin synthesis was measured at about 3 h, as observed by others [6,7,19,20]. The rate of synthesis increased progressively until about 16 h. The rate of conalbumin synthesis increased very rapidly; it was significant by 1 h, and also reached a maximum at 16 h (Fig.…”

“…The induction of these proteins is an early effect of oestrogens and the kinetics of induction differ for the two proteins [5, 7,8].…”

“…After withdrawal of oestrogen treatment, the weight of the magnum decreases markedly and the level of synthesis of the oestrogen-induced secretory proteins declines; the organ, however, remains capable of responding rapidly to secondary oestrogen stimulation by the rapid onset of egg-white protein synthesis [2,4-61. In the first 8 h of secondary stimulation by oestradiol or progesterone, the kinetics of induction of ovalbumin and conalbumin differ [5,7,8]. The increase in the synthesis of both proteins is coincident with the accumulation of their respective mRNAs [7,8].…”

“…In the first 8 h of secondary stimulation by oestradiol or progesterone, the kinetics of induction of ovalbumin and conalbumin differ [5,7,8]. The increase in the synthesis of both proteins is coincident with the accumulation of their respective mRNAs [7,8].…”

“…In the first 8 h of secondary stimulation by oestradiol or progesterone, the kinetics of induction of ovalbumin and conalbumin differ [5,7,8]. The increase in the synthesis of both proteins is coincident with the accumulation of their respective mRNAs [7,8].Tamoxifen, a non-steroidal compound [91, has been shown to act as a 'pure' antioestrogen [lo] in the secondarily stimulated chick-oviduct system. Administration of 10 mg/kg tamoxifen, at the same time as 1 mg/kg oestradiol benzoate, completely abolished the oestrogen-induced increases in tissue weight, DNA content and cytoplasmic progesterone and oestrogen receptor concentrations, whereas tamoxifen alone had no effect on these parameters [lo].…”