Imperial College London


Faculty of Natural SciencesDepartment of Life Sciences

Professor of Molecular Membrane Biology



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BibTex format

author = {Byrne, B and Fowler, PA and Templeton, AA},
journal = {Journal of Clinical Endocrinology & Metabolism},
pages = {1454--1459},
title = {Gonadotrophin surge attenuating factor suppresses progesterone augmentation of GnRH priming},
volume = {81},
year = {1996}

RIS format (EndNote, RefMan)

AB - We investigated the effects of gonadotropin surge-attenuating factor (GnSAF), inhibin, and follistatin on GnRH self-priming and its augmentation by progesterone. Two GnRH challenges, 60 min apart, were administered to rat pituitary monolayers after 90-min exposure to medium alone (control), progesterone, GnSAF, inhibin, or follistatin. Inhibin-stripped follicular fluid from superovulated women was used as a source of GnSAF bioactivity. Under control conditions, the greater response to the second GnRH challenge (peak 2, 9.2 +/- 2.1; peak 1, 4.4 +/- 0.9 ng LH/mL; P < 0.01) demonstrated GnRH self-priming. None of the treatments significantly altered the first LH peak. Progesterone markedly increased GnRH self-priming (peak 2, 12.6 +/- 2.5 ng LH/mL; P < 0.01). However, GnSAF and RU486 significantly reduced GnRH self-priming (peak 2, 4.6 +/- 0.9 and 5.6 +/- 1.6 ng LH/mL, respectively; P < 0.01). The augmentation of self-priming induced by progesterone was completely abolished by coincubation with either GnSAF or RU486 (peak 2, 7.5 +/- 1.6 and 4.3 +/- 0.9 ng LH/mL, respectively; P < 0.01). Neither inhibin nor follistatin had any effect on GnRH self-priming or its augmentation by progesterone. The actions of RU486 in the presence and absence of progesterone demonstrate a nonprogestagenic effect of RU486 on the gonadotropes. In conclusion, the suppression of GnRH self-priming, with or without progesterone augmentation, supports the hypothesis that GnSAF acts by maintaining the pituitary in an unprimed state of reduced responsiveness to GnRH.
AU - Byrne,B
AU - Fowler,PA
AU - Templeton,AA
EP - 1459
PY - 1996///
SP - 1454
TI - Gonadotrophin surge attenuating factor suppresses progesterone augmentation of GnRH priming
T2 - Journal of Clinical Endocrinology & Metabolism
VL - 81
ER -