Estrogen-Induced Cytodifferentiation of the Ovalbumin-Secreting Glands of the Chick Oviduct

The histological, ultrastructural, and biochemical changes occurring during hormone-induced cytodifferentiation of the ovalbumin-secreting glands in the chick oviduct have been studied. Marked perivascular edema is an initial response of the immature oviduct stroma to diethylstilbestrol administration and is accompanied by an interstitial migration of mononuclear cells. Mitotic activity in the immature mucosal epithelium increases within 24 hr, and glands begin to develop on days 2-4 as budlike invaginations into the subepithelial stroma. An immediate intracellular effect of the hormone is aggregation of previously dispersed ribosomes. Ribosomal zones in the nucleolus gain prominence, and there is a progressive development of rough endoplasmic reticulum in the epithelial cells. Extensive profiles of endoplasmic reticulum are present in the gland cells by day 6. Fine apical progranules appear in the epithelial cells on day 2, and ovalbumin can be measured immunochemically by day 3 at about the same time that new species of nuclear RNA have been identified. Ovalbumin granules form within condensing vacuoles in the Golgi zone and begin to be released into the lumina of the gland acini at about day 6 of the treatment.