Relationship between follicle size and gonadotrophin surge attenuating factor (GnSAF) bioactivity during spontaneous cycles in women

Citation
Pa. Fowler et al., Relationship between follicle size and gonadotrophin surge attenuating factor (GnSAF) bioactivity during spontaneous cycles in women, HUM REPR, 16(7), 2001, pp. 1353-1358
Citations number
25
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Reproductive Medicine","da verificare
Journal title
HUMAN REPRODUCTION
ISSN journal
0268-1161 → ACNP
Volume
16
Issue
7
Year of publication
2001
Pages
1353 - 1358
Database
ISI
SICI code
0268-1161(200107)16:7<1353:RBFSAG>2.0.ZU;2-N
Abstract
BACKGROUND: We have previously demonstrated that follicles less than or equ al to 11 mm diameter from women undergoing IVF contain higher concentration s of gonadotrophin surge attenuating factor (GnSAF) bioactivity than large follicles from the same ovaries. METHODS: To determine whether this finding is relevant to spontaneous cycles, follicular fluid aspirated from 37 foll icles between 3 and 25 mm in diameter from 14 pairs of ovaries from regular ly cycling women undergoing total abdominal hysterectomy and bilateral salp ingoophorectomy for benign gynaecological disease was pooled into size cate gories (3 + 4, 5 + 6, 7 + 8, 9 + 10, 11 + 12, 14 + 15, 18 and 25 mm), These pools were bioassayed for GnSAF and inhibin-A, inhibin-B and activin-ii co ncentrations were determined, RESULTS: Follicles of 5 + 6 mm diameter conta ined the highest concentrations of GnSAF bioactivity (reducing GnRH-induced LH secretion to 38 +/- 8% of control, P < 0.001), while those of 25 mm dia meter contained one quarter of this concentration (reducing GnRH-induced LH secretion to 72 +/- 2% of control, P < 0.05). GnSAF bioactivity was closel y related to follicle size (r = -0.836, P < 0.01), but not to inhibin-A, in hibin-B or activin-A concentrations. CONCLUSIONS: The finding that small fo llicles contain high concentrations of GnSAF bioactivity, which fall as fol liculogenesis progresses during spontaneous cycles, support the hypothesis that GnSAF has a role in preventing the premature onset of the LH surge in women.