Effect of oestrogen and an LH-RH agonist on the release of gonadotrophins in ovariectomized ewes deprived of LH-RH

Fraser, Hamish M.; Clarke, I. J.; McNeilly, Alan S.

doi:10.1530/jrf.0.0620131

Cited by 25 publications

(15 citation statements)

References 19 publications

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“…The positive feedback effect of oestradiol on LH release can be blocked by inhibitors of RNA and protein synthesis (Jackson, 1972(Jackson, , 1973. The prolonged negative feedback effect of oestradiol on FSH concentrations in ovariec¬ tomized ewes has previously been reported (Fraser, Clarke & McNeilly, 1981). As with LH, the initial suppression may or may not involve receptor-mediated responses via the genome.…”

Section: Discussionmentioning

confidence: 94%

Relationship between pituitary nuclear oestrogen receptors and the release of LH, FSH and prolactin in the ewe

Clarke¹,

Funder²,

Findlay³

1982

Reproduction

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Ovariectomized ewes were given a single injection (i.v.) of 100 micrograms oestradiol-17 beta. Nuclear oestrogen receptor values in the pituitary, as a function of total receptor concentrations, were 3.0 +/- 1.0% in controls, 56.0 +/- 5.4% at 1 h (P less than 0.001) and 6.5 +/- 2.1% at 6 h (P less than 0.05) after oestradiol injection. There was a fall in plasma LH values from 5.7 +/- 1.0 (preinjection) to 2.1 +/- 0.3 ng/ml (P less than 0.01) 4-6 h after oestradiol. At 13-21 h after injection plasma levels increased to 37 +/- 8 ng/ml (P less than 0.001). Plasma FSH levels declined from 840 +/- 18 to 506 +/- 48 ng/ml after 20-22 h (P less than 0.001). Plasma prolactin concentrations fell from 90 +/- 16 ng/ml before injection to 29 +/- 9 ng/ml at 1 h (P less than 0.05), and then rose to a maximum of nuclear compartmentalization of oestrogen receptors after a bolus injection of oestradiol was associated with the feedback effects of oestradiol on LH, FSH and prolactin release.

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Section: Discussionmentioning

confidence: 94%

Relationship between pituitary nuclear oestrogen receptors and the release of LH, FSH and prolactin in the ewe

Clarke¹,

Funder²,

Findlay³

1982

Reproduction

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“…Blood samples were collected at 10-min intervals for a further 4 h and at hourly intervals until 36 h after antiserum injection. (Fraser, Clarke & McNeilly, 1981). The properties of this antiserum have been described previously (Lincoln & Fraser, 1979;Fraser & McNeilly, 1982).…”

Section: Methodsmentioning

confidence: 99%

Differential effects of LH-RH immunoneutralization on LH and FSH secretion in the ewe

Fraser¹,

McNeilly²

1983

Reproduction

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“…This, however, is not definitive proof of selective brain function since the synthesis and secretion of gonadotropins in gonadotropes does not occur in the absence of the trophic input of GnRH [17,18]. Accordingly, such data as those obtained with antagonist administration, only preclude a singular action of kisspeptin on gonadotropes, a real possibility because GPR54 is expressed in the human pituitary [2,4].…”

Section: Genesismentioning

confidence: 96%

Kisspeptin expression in the brain: Catalyst for the initiation of puberty

Smith

Clarke

2007

Rev Endocr Metab Disord

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In 2003, two independent groups of researchers discovered almost simultaneously that inactivating mutations of the G protein coupled receptor, GPR54, cause hypogonadotropic hypogonadism in mice and men. Since this discovery, kisspeptins, the natural ligands for GPR54, have been thrust into the reproductive neuroendocrine spotlight, as major regulators of GnRH function. Kisspeptins are the peptide products of the KiSS-1 gene, and potently stimulate gonadotrophin secretion when administered either centrally or peripherally. Expression of KiSS-1 has been localised to specific regions of the hypothalamus in many species and is regulated by gonadal steroids and across the estrous cycle. It appears that kisspeptin transmits steroid feedback signals to GnRH cells, especially the positive feedback effect of estrogen that causes the preovulatory GnRH/LH surge. Importantly, kisspeptin function appears to be fundamental to the initiation of puberty.

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Effect of oestrogen and an LH-RH agonist on the release of gonadotrophins in ovariectomized ewes deprived of LH-RH

Abstract: Summary. Endogenous LH-RH

Cited by 25 publications

References 19 publications

Relationship between pituitary nuclear oestrogen receptors and the release of LH, FSH and prolactin in the ewe

Relationship between pituitary nuclear oestrogen receptors and the release of LH, FSH and prolactin in the ewe

Differential effects of LH-RH immunoneutralization on LH and FSH secretion in the ewe

Kisspeptin expression in the brain: Catalyst for the initiation of puberty

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