Naturally occurring antihormones: secretion of FSH antagonists by women treated with a GnRH analog
Dahl, K.D.; Bicsak, T.A.; Hsueh, A.J.
Science 239(4835): 72-74
1988
ISSN/ISBN: 0036-8075 PMID: 3122320 DOI: 10.1126/science.3122320Document Number: 353637
Follicle-stimulating hormone (FSH) is a glycoprotein essential for gonadal development and steroidogenesis. Recent studies suggest that deglycosylation of FSH results in the formation of antagonistic proteins that are capable of binding to gonadal receptors but that are devoid of bioactivity. Treatment of hypogonadal women with an antagonist of gonadotropin-releasing hormone substantially decreased serum FSH bioactivity with minimal changes in immunoreactivity. Chromatofocusing and size fractionation of the serum samples indicated the secretion of immunoreactive FSH isoforms that are devoid of bioactivity but that are capable of blocking FSH action in ovarian granulosa cells. These findings provide the first demonstration of naturally occurring circulating antihormones. These FSH antagonists may play an important role in the physiology and pathophysiology of the gonads.