Imperial College London

ProfessorBernadetteByrne

Faculty of Natural SciencesDepartment of Life Sciences

Professor of Molecular Membrane Biology
 
 
 
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Contact

 

+44 (0)20 7594 3004b.byrne Website

 
 
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Location

 

504Sir Ernst Chain BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Fowler:1994,
author = {Fowler, PA and Cunningham, P and Fraser, M and MacGregor, F and Byrne, B and Pappas, A and Messinis, IE and Templeton, A},
journal = {Journal of Endocrinology},
pages = {45--54},
title = {Ciruclating gonadotrphin surge attenuating factor from superovulated women suppresses in vitro gonadotrophin-releasing hormone self-priming},
volume = {143},
year = {1994}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - A perifusion system based on ovine pituitary tissue explants was used to investigate the effects of follicular fluid (hFF) and serum from superovulated women on pituitary responsiveness to gonadotrophin-releasing hormone (GnRH). The specific aims of the study were to determine both if gonadotrophin surge-attenuating factor (GnSAF) bioactivity is present in the peripheral circulation as well as in the follicles of superovulated women and if GnSAF suppresses GnRH self-priming in vitro. Two pulses of GnRH, 1 h apart, produced marked peaks in LH secreted from control chambers, with GnRH self-priming evident in the significant difference between the first (134.4 +/- 1.7 - 232.1 +/- 24.0% of basal secretion) and second (183.9 +/- 15.8 - 313.9 +/- 14.0% of basal secretion) LH peaks. Both follicular fluid and serum pooled from two different groups of women produced marked suppression of the first (unprimed) and second (primed) LH peaks. The hFF reduced the first LH peak to 69.6 +/- 7.8 and 60.2 +/- 9.7% and the second LH peak to 57.4 +/- 6.7 and 42.6 +/- 6.5% of control LH secretion. Overall, the serum reduced the first and second LH peaks to 76.8 +/- 4.2 and 62.9 +/- 3.6% of control respectively. These results demonstrated that GnSAF bioactivity suppresses GnRH self-priming, and is present in both the peripheral circulation and hFF. The same material administered to dispersed ovine pituitary monolayers produced similar marked suppression of GnRH-induced LH secretion, with approximately 50-fold less GnSAF bioactivity in serum compared with hFF. Combined doses of oestradiol and progesterone, or hFF from large follicles containing little GnSAF, produced stimulation of GnRH-induced LH secretion and GnRH self-priming (second peaks 78.1 +/- 38.9 and 27.4 +/- 15.7% respectively higher than first peaks). Thus, in conclusion, GnSAF in hFF and serum markedly attenuated both unprimed and primed pituitary response to GnRH, virtually abolishing the GnRH self-priming effect.
AU - Fowler,PA
AU - Cunningham,P
AU - Fraser,M
AU - MacGregor,F
AU - Byrne,B
AU - Pappas,A
AU - Messinis,IE
AU - Templeton,A
EP - 54
PY - 1994///
SP - 45
TI - Ciruclating gonadotrphin surge attenuating factor from superovulated women suppresses in vitro gonadotrophin-releasing hormone self-priming
T2 - Journal of Endocrinology
VL - 143
ER -