Identification of gonadotrophin surge-inhibiting factor (GnSIF)/attenuin in human follicular fluid
Source: Human Reproduction, Volume 11, Number 3, March 1996 , pp. 490-496(7)
Publisher: Oxford University Press
Abstract:Evidence from several laboratories suggests that the ovaries of many species produce a non-steroidal factor called gonadotrophin surge-inhibiting or attenuating factor (GnSIF) which may regulate the response of the pituitary to gonadotrophin-releasing hormone (GnRH) and as such, may modulate the timing and/or amplitude of the lutein-izing hormone (LH) surge. We have recently isolated a candidate GnSIF from porcine follicular fluid (PFF). Porcine GnSIF is a 69 kDa protein which has undetect-able inhibin and follistatin immunological and biological activity. The present study was designed to purify and identify GnSIF from human follicular fluid. GnSIF activity was measured as suppression of GnRH-stimulated LH secretion from rat pituitary cells in primary culture. Human follicular fluid (-500 ml) was recovered from patients undergoing in-vitro fertilization (FVF). GnSIF was purified by heparin-sepharose, Q-sepharose, S-sepharose, and hydrophobic interaction chromatography followed by iso-electric focusing. Gel electrophoresis and Western blot were used to identify human GnSIF and compare it with porcine GnSIF. Using these steps, we obtained a highly-purified preparation of GnSIF that manifests in-vitro bioactivity and chromatography characteristics similar to those observed for porcine GnSIF and that hybridizes with a porcine GnSIF antibody. Following treatment with human chorionic gonadotrophin/human menopausal gonadotrophin (HMG/HCG), human follicular fluid contained roughly 25% of the GnSIF (per mg protein) present in porcine follicular fluid. We conclude that GnSIF is present in human follicular fluid and may participate in the regulation of gonadotrophin secretion in this species.
Document Type: Research article
Affiliations: 1: <institution>Department of Obstetrics and Gynecology, Ohio State University</institution> <addr-line>Fifth Floor Means Hall, 1654 Upham Drive, Columbus, OH 43210, USA</addr-line>, 2: ,
Publication date: 1996-03-01
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.