An Homologous Radioimmunoassay for Chicken Follicle-Stimulating Hormone: Observations on the Ovulatory Cycle

Scanes, Colin G.; Godden, Patricia M. M.; Sharp, P. J.

doi:10.1677/joe.0.0730473

Cited by 72 publications

(21 citation statements)

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“…Early studies [10,11] demonstrated that granulosa cell condition [12] provided direct evidence that the granulosa cells of the four largest follicles of laying hen are the primary source of inhibin in the chicken. Our findings that the plasma FSH peak occurred 12 h before ovulation are in agreement with the reports of Scanes et al [6], and in contrast to the report of Vanmonfort et al [7].…”

Section: Discussionsupporting

confidence: 93%

Plasma Concentrations of Immunoreactive (ir)-Inhibin, Gonadotropins and Steroid Hormones during the Ovulatory Cycle of the Duck

Yang

Medan

Arai

et al. 2005

Journal of Reproduction and Development

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Abstract. The present study was undertaken to determine changes in circulating levels of immunoreactive (ir)-inhibin, FSH, LH, estradiol-17β, progesterone, and testosterone during the ovulatory cycle of Shao ducks. Serial blood samples were taken from two groups of laying ducks for measurement of ir-inhibin, gonadotropins, and steroid hormones at 2 h intervals for 24 h. Plasma concentrations of ir-inhibin did not change significantly during the ovulatory cycle. The highest level of plasma ir-inhibin was observed 6 h prior to ovulation, which coincided with a decreased level of plasma FSH. One FSH surge was found 12 h after ovulation. Estradiol-17β, progesterone, and testosterone were also determined during the ovulatory cycle. Two peak values were detected for estradiol-17β 8 h before ovulation and 4 h after ovulation, while progesterone started to increase 4 h before ovulation and reached a peak at ovulation. The highest level of plasma testosterone was detected around the time of ovulation. These results suggest that inhibin may be involved in the control of FSH secretion during the ovulatory cycle. In addition, both LH and progesterone are of importance in the ovulation process of Shao ducks.

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Section: Discussionsupporting

confidence: 93%

Plasma Concentrations of Immunoreactive (ir)-Inhibin, Gonadotropins and Steroid Hormones during the Ovulatory Cycle of the Duck

Yang

Medan

Arai

et al. 2005

Journal of Reproduction and Development

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“…This concept of release from inhibition is relevant because it has recently been established that all hen follicles within the cohort from which selection occurs (both whole follicles as well as the isolated granulosa layers from these follicles) express FSH-R mRNA (Woods and Johnson; unpublished data). Assuming similar levels of receptor translation and functional coupling to signaling pathways prior to the selection process, one would expect equal follicle exposure to circulating FSH [37], and thus the potential for multiple follicles to simultaneously begin FSH-promoted differentiation. Results presented previously and herein are consistent with MAP kinase/Erk activity serving as an effective inhibitor of premature granulosa cell differentiation.…”

Section: Discussionmentioning

confidence: 99%

Cellular Mechanisms and Modulation of Activin A- and Transforming Growth Factor β-Mediated Differentiation in Cultured Hen Granulosa Cells1

Johnson

Bridgham

Woods

2004

Biology of Reproduction

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Undifferentiated granulosa cells from prehierarchal (6- to 8-mm-diameter) hen follicles express very low to undetectable levels of LH receptor (LH-R) mRNA, P450 cholesterol side chain cleavage (P450scc) enzyme activity, and steroidogenic acute regulatory (StAR) protein, and produce negligible progesterone, in vitro, following an acute (3-h) challenge with either FSH or LH. It has previously been established that culturing such cells with FSH for 18-20 h induces LH-R, P450scc, and StAR expression, which enables the initiation of progesterone production. The present studies were conducted to characterize the ability of activin and transforming growth factor (TGF) beta, both alone and in combination with FSH, to promote hen granulosa cell differentiation, in vitro. A 20-h culture of prehierarchal follicle granulosa cells with activin A or transforming growth factor beta (TGFbeta)1 increased LH-R mRNA levels compared with control cultured cells. Activin A and TGFbeta1 also promoted FSH-receptor (FSH-R) mRNA expression when combined with FSH treatment. Neither activin A nor TGFbeta1 alone stimulated progesterone production after 20 h culture. However, preculture with either factor for 20 h (to induce gonadotropin receptor mRNA expression) followed by a 3-h challenge with FSH or LH potentiated StAR expression and progesterone production compared with cells challenged with gonadotropin in the absence of activin A or TGFbeta1 preculture. Significantly, activation of the mitogen-activated protein (MAP) kinase pathway with transforming growth factor alpha (TGFalpha) (monitored by Erk phosphorylation) blocked TGFbeta1-induced LH-R expression, and this effect was associated with the inhibition of Smad2 phosphorylation. We conclude that a primary differentiation-inducing action of activin A and TGFbeta1 on hen granulosa cells from prehierarchal follicles is directed toward LH-R expression. Enhanced LH-R levels subsequently sensitize granulosa cells to LH, which in turn promotes StAR plus P450scc expression and subsequently an increase in P4 production. Significantly, the finding that TGFbeta signaling is negatively regulated by MAP kinase signaling is proposed to represent a mechanism that prevents premature differentiation of granulosa cells.

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“…LH, FSH, prolactin, growth hormone and androgens were measured using the radioimmunoassay systems described by Follett et al (1972), Scanes et al (1977), Lea et al (1982), Harvey and Scanes (1977) and Williams and Sharp (1978), respectively. All samples for each hormone were measured at one time to avoid variation between assays.…”

Section: Methodsmentioning

confidence: 99%

Plasma concentrations of Luteinising hormone, follicle stimulating hormone, androgen, growth hormone, Prolactin, Thyroxine and Triiodothyronine during growth and sexual development in the cockerel

Sterling

Sharp

Klandorf

et al. 1984

British Poultry Science

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Changes in concentrations of plasma luteinising hormone (LH), follicle stimulating hormone (FSH), androgen, growth hormone (GH), prolactin (Prl), thyroxine (T4) and triiodothyronine (T3) were measured during growth and sexual maturation in broiler cockerels reared in continuous light to 7 weeks and 14 h light/d thereafter. Concentrations of LH and FSH began to increase between 13 and 15 weeks, while those of androgens increased between 16 and 17 weeks. FSH concentration increased faster than that of LH. Concentrations of GH and Prl were high at 3 weeks; that of GH decreasing progressively between 3 and 14 weeks of age and thereafter remaining low, while that of Prl was low between 5 and 9 weeks, relatively high between 10 and 13 weeks, and then temporarily decreasing before increasing progressively during sexual maturation. Concentrations of T3 and T4 were higher in juvenile than in adult birds.

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An Homologous Radioimmunoassay for Chicken Follicle-Stimulating Hormone: Observations on the Ovulatory Cycle

Cited by 72 publications

References 0 publications

Plasma Concentrations of Immunoreactive (ir)-Inhibin, Gonadotropins and Steroid Hormones during the Ovulatory Cycle of the Duck

Plasma Concentrations of Immunoreactive (ir)-Inhibin, Gonadotropins and Steroid Hormones during the Ovulatory Cycle of the Duck

Cellular Mechanisms and Modulation of Activin A- and Transforming Growth Factor β-Mediated Differentiation in Cultured Hen Granulosa Cells1

Plasma concentrations of Luteinising hormone, follicle stimulating hormone, androgen, growth hormone, Prolactin, Thyroxine and Triiodothyronine during growth and sexual development in the cockerel

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