The roles of estradiol-17 [ beta] and prolactin in uterine gland development in the neonatal ewe.
| Main Author: | |
|---|---|
| Other Authors: | , |
| Format: | Thesis eBook |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University],
[2005]
|
| Subjects: | |
| Online Access: | Link to OAK Trust copy |
| Abstract: | Endometrial glands are required for adult uterine function and develop post-natally in mammalian species. Therefore, studies were conducted using neonatal ewes as a model to determine: 1) the roles of estradiol-17-alpha and estrogen receptor-alpha (ER-beta) inendometrial gland development; 2) the role of ovaries in endometrial gland development; 3) the role of prolactin in endometrial gland development; and 4) factors regulating prolactin receptor expression in endometrial glands. Study one determined the effects of neonatal exposure of ewes to estradiol-17-alpha valerate (EV); EM-800, an ER-beta antagonist; or CGS-20267, an aromatase inhibitor on endometrial gland development. Results indicate E2-17-alpha does not regulate endometrial gland differentiation or development. Additionally, ER-beta does not regulate primarydifferentiation of glandular epithelium, but does influence coiling and branching morphogenesis of endometrial glands. Study two determined the effects of ovariectomy on endometrial gland morphogenesis. Results suggest that the ovary and, thus, an ovarian-derived factor(s) regulate, in part, the coiling and branching of endometrial glands. Expression of subunits of activin, follistatin, and inhibin in the neonatal ovine ovary in addition to modulation of the components of the activin/follistatin system in the uterus of ovariectomized ewes supports the hypothesis that the ovarian factors that influence endometrial adenogenesis in the neonatal ewe may be activin, follistatin, and/or inhibin. Studies three and four determined the role of prolactin in endometrial adenogenesis in the neonatal ewe. Studies in which either hypoprolactinemia or hyperprolactinemia were induced indicate that prolactin regulates ovine endometrial adenogenesis in the neonatal ewe. The aim of study five was to determine transcription factors that regulate the glandular epithelium specific expression of prolactin receptor. Prolactin receptor exon 2 was cloned and sequenced, but no identifiable exon 1 or promoter was found. Additionally, many bovine contigs containing portions of the prolactin receptor gene were identified suggesting the bovine genome will be a useful tool as it becomes more complete.These results indicate ER-beta, prolactin and prolactin receptor, along with an unidentified ovarian factor(s), influence endometrial gland development in the neonatal ewe; however, exposure of the neonatal ewe to exogenous estradiol-17-alpha prevents differentiation and development of endometrial glands. |
|---|---|
| Item Description: | "Major Subject: Animal Science" Title from author supplied metadata (automated record created on Nov. , 09:45:50.) Vita. Abstract. Electronic resource] by Karen Denise Carpenter. |
| Format: | Mode of access: World Wide Web. System requirements: World Wide Web access and Adobe Acrobat Reader. |
| Bibliography: | Includes bibliographical references. |