Direct luteotrophic effect of oestradiol-17  on pig corpora lutea

Conley, Alan J; Ford, Stephen P.

doi:10.1530/jrf.0.0870125

Cited by 51 publications

(29 citation statements)

References 10 publications

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“…In rabbits, estradiol is critical for maintenance of progesterone production [33]. In pigs, estradiol implants promote greater CL development than nonimplanted CL in the same animal [18,34]. Also, porcine CL implanted with a microdialysis system and infused with estradiol respond with an increase in progesterone, an effect blocked by tamoxifen [19].…”

Section: Discussionmentioning

confidence: 99%

Acquisition of Luteolytic Capacity: Changes in Prostaglandin F2α Regulation of Steroid Hormone Receptors and Estradiol Biosynthesis in Pig Corpora Lutea1

Diaz

Wiltbank

2004

Biology of Reproduction

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The pig corpora lutea (CL) acquires luteolytic capacity at about Day 13 of the estrous cycle, after which luteolysis occurs in response to prostaglandin F2alpha (PGF2alpha) treatment. We postulated that differences in transcription factors such as the steroid hormone receptors may be responsible for the differences in PGF2alpha-induced gene expression after acquisition of luteolytic capacity. In these studies, we evaluated the effect of PGF2alpha on luteal expression of receptors for progesterone (nuclear and membrane progesterone receptor [PR]), estradiol (ERalpha and ERbeta), glucocorticoid, androgens, and two enzymes in estradiol synthesis (P450-17alpha and aromatase). Two experiments were conducted to examine the early (0.5 h, experiment I) and late (10 h, experiment II) effects of PGF(2alpha) on the expression of these receptors in CL with (Day 17) or without (Day 9) luteolytic capacity. PGF2alpha decreased ERalpha mRNA (35%) and increased ERbeta mRNA (558%) and protein (376%) only in Day 17 CL and not Day 9. The estradiol biosynthetic pathway was upregulated by PGF2alpha in Day 17 CL but not Day 9 CL, with a dramatic increase in aromatase mRNA and luteal estradiol content. Nuclear PR was not affected by PGF2alpha, but was greater (176%) in Day 9 CL, while a putative membrane PR was greater (156%) in Day 17 than Day 9 CL. There were no detectable changes in glucocorticoid or androgen receptor mRNA. Thus, luteolytic capacity is associated with upregulation of estradiol biosynthesis, which in conjunction with increased ERbeta expression and altered PR expression may promote luteolysis in the pig CL.

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Section: Discussionmentioning

confidence: 99%

Acquisition of Luteolytic Capacity: Changes in Prostaglandin F2α Regulation of Steroid Hormone Receptors and Estradiol Biosynthesis in Pig Corpora Lutea1

Diaz

Wiltbank

2004

Biology of Reproduction

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“…These pigs were evaluated for estrous behavior twice daily by use of an intact boar. To obtain preovulatory follicles or early CL (corpora hemorrhagica), some gilts were evaluated for estrous behavior every 8 h beginning on Day 16 after estrus, and their ovaries were collected under halothane anesthesia [4] at 18-24 h after first detection of estrus. To evaluate CL, ovaries were obtained at slaughter from gilts on Day 2 or 12 after estrus.…”

Section: Methodsmentioning

confidence: 99%

Immunohistochemical Localization of 3β-Hydroxysteroid Dehydrogenase and P450 17α-Hydroxylase during Follicular and Luteal Development in Pigs, Sheep, and Cows1

Conley

Kaminski

Dubowsky

et al. 1995

Biology of Reproduction

118

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Follicular and luteal morphology and steroidogenic function were investigated by immunohistochemistry for cytochrome P450 17 alpha-hydroxylase (P450c17) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) during the estrous cycle in pigs, sheep, and cows. The theca interna of all species expressed P450c17 during follicular development. In the pig, this constituted a continuous layer of cells around the follicle, but a sheath of cells lining the basement membrane appeared not to express P450c17. Neither was expression of P450c17 in ovine and bovine follicles uniform throughout the theca interna. In these two species, a beaded appearance was given by P450c17, since it was expressed in some regions but not in others. Therefore, staining for P450c17 defined functional sub-populations of cells within the theca interna of pigs, sheep, and cows. Ovulation was associated with a decrease in P450c17 in all species, but some expression persisted in theca-derived cells of developing and mature porcine CL. Expression of 3 beta-HSD in the preovulatory follicle was confined to the theca of the pig and sheep; in contrast, in the cow, it was highest in the granulosa. In general, 3 beta-HSD expression appeared to be greater in porcine than ovine or bovine follicles, the physiological relevance of which is discussed. Porcine and ovine theca continued to express 3 beta-HSD after ovulation, and granulosa-derived cells increased their 3 beta-HSD expression markedly as they luteinized in all three species. During early luteal development in pigs and sheep, theca-derived cells with high 3 beta-HSD encircled luteal lobules, but these cells appeared throughout the parenchyma of the mature CL. Luteal regression in sheep and cows was typified by the loss of many cells expressing 3 beta-HSD, whereas others, adjacent to them, appeared to be intact without loss of enzyme expression. These data further define differences in steroidogenesis during follicular and luteal development among the pig, sheep, and cow.

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“…In addition to the alteration of PG movement from the uterine endometrium, release of estrogen from the expanding conceptuses can have a direct luteotrophic effect on the CL (Conley and Ford 1989 ) as well as stimulating a localized increase in endometrial vascular permeability King 1988 , 1995 ) and an overall increase in uterine blood fl ow (Ford et al 1982 ;Ford and Stice 1985 ). During conceptus elongation and the early peri-implantation period, the endometrium increases the release of a number of growth factors and cytokines such as epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), fi broblast growth factor 7 (FGF7), vascular endothelial growth factor (VEGF), interleukin 6 (IL-6), transforming growth factor beta (TGFβ), and leukemia inhibitory factor (LIF) (see review Bazer et al 2010 ;Geisert et al 2014 ).…”

Section: Luteostatic Mechanism Of CL Maintenancementioning

confidence: 99%

Implantation and Establishment of Pregnancy in the Pig

Geisert¹,

Johnson²,

Burghardt

2015

Regulation of Implantation and Establishment of Pregnancy in Mammals

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Establishment of pregnancy in the pig is initiated through the release of estrogens from the rapidly elongating conceptuses. Release of estrogens from the developing conceptuses alters the movement of endometrial prostaglandin F2α from being released into the vasculature (endocrine secretion) to sequestering in the uterine lumen (exocrine secretion). Rapid trophoblast elongation, which is unique to the pig, may be triggered through production of interleukin 1β2 (IL1B2) by conceptuses. Trophoblast elongation through the uterine horns provides the mechanism to allow conceptus-endometrial interactions essential for the implantation, placentation, and maintenance of pregnancy in the pig. This chapter provides current information on conceptus signaling pathways and endometrial responses to those conceptus factors leading to establishment of pregnancy.

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Direct luteotrophic effect of oestradiol-17 on pig corpora lutea

Cited by 51 publications

References 10 publications

Acquisition of Luteolytic Capacity: Changes in Prostaglandin F2α Regulation of Steroid Hormone Receptors and Estradiol Biosynthesis in Pig Corpora Lutea1

Acquisition of Luteolytic Capacity: Changes in Prostaglandin F2α Regulation of Steroid Hormone Receptors and Estradiol Biosynthesis in Pig Corpora Lutea1

Immunohistochemical Localization of 3β-Hydroxysteroid Dehydrogenase and P450 17α-Hydroxylase during Follicular and Luteal Development in Pigs, Sheep, and Cows1

Implantation and Establishment of Pregnancy in the Pig

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