Endometrial development and adenogenesis in the neonatal pig: effects of estradiol valerate and the antiestrogen ICI 182,780

• Published in: Biology of reproduction Vol. 61; no. 1; pp. 253 - 263
• Main Authors: Tarleton, B.J, Wiley, A.A, Bartol, F.F
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01-07-1999
• Subjects: Aging; Animals; Animals, Newborn - growth & development; Biological and medical sciences; DNA - biosynthesis; DNA replication; endometrial glands; endometrium; Endometrium - chemistry; Endometrium - drug effects; Endometrium - growth & development; epithelium; Epithelium - chemistry; Epithelium - metabolism; estradiol; Estradiol - analogs & derivatives; Estradiol - pharmacology; Estrogen Antagonists - pharmacology; estrogen receptors; Female; Fulvestrant; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; hormone antagonists; In Situ Hybridization; localization; Mammalian female genital system; messenger RNA; Morphology. Physiology; neonatal development; Organ Size; postnatal development; Receptors, Estrogen - genetics; Receptors, Estrogen - physiology; RNA, Messenger - analysis; Stromal Cells - chemistry; swine; Swine - growth & development; uterus; Uterus - drug effects; Uterus - growth & development; Vertebrates: reproduction; weight; Estrogen; Histology; Gene expression; Postnatal development; Ovarian hormone; Pig; Vertebrata; Mammalia; Uterus; Female genital system; Development; Artiodactyla; Sex steroid hormone; Morphometry; Ungulata; Endometrium; Hormonal receptor
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod61.1.253

In the pig, appearance of endometrial glands between birth (postnatal day [PND] 0) and PND 14 involves development of estrogen
receptor-α-positive (ER+) phenotype by, and increased DNA synthesis in, nascent glandular epithelium (GE). To determine whether
ER activation is required for this process, gilts were treated daily with either vehicle, the antiestrogen ICI 182,780 (ICI),
estradiol-17β valerate (EV), or both ICI and EV. Treatments began on PND 0, before onset of adenogenesis, or on PND 7, after
onset of gland proliferation. Uteri obtained on PNDs 7 and 14 (study one) or on PND 14 (study two) were weighed; uterine histology
was evaluated; DNA synthesis in luminal epithelium and GE was characterized by determining 5-bromo-2′-deoxyuridine (BrdU)
labeling index; and patterns of ER mRNA expression were evaluated in situ (study one). Gland genesis was inhibited by ICI,
which decreased gland penetration depth by PND 14 in study one, both endometrial thickness and BrdU-labeling index in GE in
study two, and increased stromal cell compaction in both studies. Uterotropic effects of EV included increased gland development
and epithelial BrdU labeling and decreased stromal compaction. These effects were inhibited by coadministration of ICI. Treatments
did not alter ER mRNA expression, which remained limited to stroma and GE. Data indicate that endometrial maturation and adenogenesis
in the neonatal pig require expression and activation of a functional ER system.