Interaction of prostaglandin F2alpha and gonadotropin-releasing hormone on progesterone and estradiol production in human granulosa-luteal cells

Väänänen, Jeffrey E.; Tong, Brenda Li Pak; Väänänen, Cé ine C.M.; Chan, Ivan Hok Yue; Yuen, Basil Ho; Leung, Peter C.K.

doi:10.1095/biolreprod57.6.1346

Cited by 39 publications

(20 citation statements)

References 39 publications

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“…Collectively, oviductal GnRH may have a stimulatory/ inhibitory role to play in progesterone production through luteotropic/luteolytic effects (as reported in human by Vaananen et al 1997) depending upon the stage of pregnancy in rats. The exact mechanism governing the pathways by which oviductal GnRH may either promote or suppress progesterone secretion from the ovary during pregnancy in rats requires further investigation.…”

Section: Discussionmentioning

confidence: 92%

Localization of Immunoreactive Gonadotropin-releasing Hormone and Relative Expression of Its mRNA in the Oviduct During Pregnancy in Rats

Sengupta

Baker

Chakrabarti

et al. 2007

J Histochem Cytochem.

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S U M M A R Y This study was designed to determine the cellular and ultrastructural distribution of the gonadotropin-releasing hormone (GnRH) and the relative expression of its mRNA in the oviduct of rats during different time points (days 7, 9, 16, and 20) of pregnancy. Immunofluorescent localization and confocal microscopic techniques were used to determine the cellular distribution of GnRH in the oviduct. Immunogold electron microscopy indicated its localization at the ultrastructural level, and real-time PCR was used to study the expression pattern of GnRH mRNA in the oviduct during pregnancy. In general, GnRH was localized within the epithelial cells lining the oviductal lumen at each selected time point. A strong correlation between the fluorescence intensity of GnRH-immunoreactive cells and the relative expression of GnRH mRNA was noted on days 7 and 16, followed by a plateau by day 20. At the ultrastructural level, uniform labeling of colloidal gold particles was observed in secretory vesicles and lamella of the luminal epithelium as well as the lumen of the oviduct.Collectively, these results demonstrate for the first time that the oviductal epithelium synthesizes and secretes the decapeptide GnRH during pregnancy in rats, which may have a possible role in postimplantation embryonic development and the maintenance of pregnancy. (J Histochem Cytochem 55:525-534, 2007)

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Section: Discussionmentioning

confidence: 92%

Localization of Immunoreactive Gonadotropin-releasing Hormone and Relative Expression of Its mRNA in the Oviduct During Pregnancy in Rats

Sengupta

Baker

Chakrabarti

et al. 2007

J Histochem Cytochem.

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“…In many studies of the ovarian receptor, the affinity of mammalian GnRH was low (ϳ10 Ϫ6 ) [10,38,39]. Only after cells are in culture for 4 days have low concentrations produced a response [40,41]. In addition, the presence of the mammalian GnRH peptide in the ovary could not be demonstrated at the concentration needed for biological activity [42].…”

Section: Discussionmentioning

confidence: 99%

Action of Gonadotropin-Releasing Hormone II on the Baboon Ovary1

Siler-Khodr

Grayson

Eddy

2003

Biology of Reproduction

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The content, binding affinity, and bioactivity of chicken II GnRH (GnRH II) and a stable analogue of GnRH II (GnRH II analogue) in the baboon ovary were studied. Although mammalian GnRH is rapidly degraded by baboon ovarian extracts, we designed a GnRH II analogue that is stable to ovarian enzymatic degradation. This analogue binds to the ovarian membranes with high affinity (41 +/- 3 nM), having 20-fold the affinity of a potent mammalian GnRH analogue. The bioactivity of GnRH II and this GnRH II analogue on the regulation of ovarian progesterone release was compared with that for a potent mammalian GnRH analogue using a baboon granulosa cell culture system. Both GnRH II and GnRH II analogue produced significant inhibition of progesterone release from the granulosa cells (P < 0.03 and P < 0.005, respectively), with a greater reduction observed using the GnRH II analogue. After 24 h in culture, this GnRH II analogue produced a 59% +/- 5% inhibition of progesterone with a concentration as low as 1 nM. Maximal inhibition of 75% +/- 1% was attained with 10 nM GnRH II analogue. The endogenous GnRH II content in the baboon ovary was 5-14 pmoles/g protein. The release of endogenous GnRH II from granulosa cells was observed throughout the 48 h in culture. These studies demonstrated the presence of high enzymatic activity for the degradation of mammalian GnRH in the ovary, whereas this GnRH II analogue was stable. High-affinity binding sites for this GnRH II analogue were also found. GnRH II and this GnRH II analogue can regulate progesterone production from baboon granulosa cells, suggesting that GnRH II is a potent regulator of ovarian function.

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“…Even though GnRH is primarily known for its role in the regulation of gonadotropin secretion from the pituitary, GnRH also modulates gonadotropin-stimulated ovarian steroidogenesis, demonstrating a direct action of the peptide in the ovary (Peng et al 1994, Anderson et al 1996, Vaananen et al 1997. In a recent study, GnRH mRNA levels in human granulosa-luteal cells were reduced by treatment with estradiol for 24 h, whereas the GnRH receptor mRNA levels were increased by short-term treatment (6 h) but diminished by long-term estradiol treatment (48 h) indicating that estradiol regulates the expression of GnRH and its receptor in the ovary .…”

Section: Figurementioning

confidence: 99%

“…There is evidence that GnRH and its binding sites are also expressed in the ovary (Peng et al 1994). GnRH may affect ovarian steroidogenesis possibly as a local autocrine/paracrine regulator by modulation of the gonadotropin-stimulated steroidogenesis in the ovary (Peng et al 1994, Vaananen et al 1997. It has also been shown that in the rat ovary local actions of GnRH are predominantly inhibitory .…”

Section: Introductionmentioning

confidence: 99%

Autoregulation of the gonadotropin-releasing hormone (GnRH) system during puberty: effects of antagonistic versus agonistic GnRH analogs in a female rat model

Roth

Schricker

Lakomek

et al. 2001

Journal of Endocrinology

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To address whether gonadotropin-releasing hormone (GnRH) regulates its own expression and the expression of its receptor in the hypothalamus and ovary, we treated five groups of prepubertal/peripubertal female rats from postnatal days 25-36 with either the GnRH agonist triptorelin (TRIP) or the GnRH antagonist cetrorelix (CET), each 10 or 100 µg/day, or a placebo. We compared their effects regarding pubertal development, serum gonadotropins and the expression of GnRH and GnRHreceptor in the hypothalamus, pituitary, ovary and uterus. Onset of puberty was determined by vaginal opening, and expression levels of GnRH and GnRH-receptor were determined using either quantitative real-time PCR or competitive RT-PCR. Onset of puberty was retarded by both analogs but CET (100 µg/day) inhibited while TRIP (10 and 100 µg/day) stimulated serum gonadotropins (P<0·05). The expression of GnRH in the preoptic area did not show significant differences among the treatment groups but ovarian GnRH mRNA levels were significantly stimulated by CET (100 µg/day). GnRH mRNA could not be detected in the uterus by either real-time PCR or competetive RT-PCR. The GnRH-receptor expression in the hypothalamus (preoptic area and mediobasal hypothalamus) did not vary among any of the groups, whereas in the pituitary GnRH-receptor mRNA levels were stimulated by TRIP (10 µg/day) but inhibited by CET (100 µg/day). In contrast, in the ovary GnRHreceptor mRNA levels were inhibited by both TRIP (100 µg/day) and CET (100 µg/day). Interestingly, the GnRH-receptor was even expressed in the uterus where it was strongly stimulated by both CET and TRIP in a dose-related manner. This shows that in addition to their different pituitary effects, the GnRH analogs cetrorelix and triptorelin exert different actions at the hypothalamic, ovarian and uterine level. This study also demonstrates an organ-specific regulation of GnRH and GnRH-receptor gene expression which is likely part of a local autoregulatory system. We conclude that the ovarian and uterine effects of GnRH analogs must be considered in addition to their known pituitary effects when deciding which GnRH analog is most suitable for treating precocious puberty.

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Interaction of prostaglandin F2alpha and gonadotropin-releasing hormone on progesterone and estradiol production in human granulosa-luteal cells

Cited by 39 publications

References 39 publications

Localization of Immunoreactive Gonadotropin-releasing Hormone and Relative Expression of Its mRNA in the Oviduct During Pregnancy in Rats

Localization of Immunoreactive Gonadotropin-releasing Hormone and Relative Expression of Its mRNA in the Oviduct During Pregnancy in Rats

Action of Gonadotropin-Releasing Hormone II on the Baboon Ovary1

Autoregulation of the gonadotropin-releasing hormone (GnRH) system during puberty: effects of antagonistic versus agonistic GnRH analogs in a female rat model

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