Gonadotropin surge-attenuating factor bioactivity in serum from superovulated women is not blocked by inhibin antibody.
Primary pituitary cultures from adult female rats were used to investigate gonadotropin surge attenuating factor (GnSAF) bioactivity. Serum from superovulated women was charcoal-treated and incubated with either an inhibin antibody (MC4), normal sheep serum (NSS), or serum-free defined medium (SFDM) before addition to cell culture. The reduction in GnRH-induced LH secretion (GnSAF bioactivity) produced by the serum (30.1 +/- 6.5%, p < 0.001, of control) was not altered by prior incubation with either MC4 or NSS (24.9 +/- 3.6 and 23.2 +/- 2.7%, p < 0.001, of control, respectively). This indicates that GnSAF bioactivity present in serum from superovulated women is not entirely attributable to inhibin. Recombinant human inhibin reduced basal FSH secretion to 24.6 +/- 4.7% (p < 0.001) of the control value. However, this was totally abolished by prior incubation with MC4, but not NSS. We have also shown that ovarian steroids are not responsible for GnSAF bioactivity in vitro. In conclusion, in contrast to findings in superovulated rats, inhibin antibody did not block GnSAF bioactivity in serum from superovulated women.
Byrne
B
B
Department of Obstetrics and Gynaecology, University of Aberdeen, Foresterhill, United Kingdom.
Fowler
P A
PA
Fraser
M
M
Culler
M D
MD
Templeton
A
A
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001667:Binding, Competitive; D002478:Cells, Cultured; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D015571:Follicular Fluid / Q000378:metabolism; D042341:Gonadal Hormones; D012739:Gonadal Steroid Hormones / Q000037:antagonists & inhibitors / Q000097:blood* / Q000494:pharmacology; D006801:Humans; D007265:Inhibins / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism; D011506:Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D012756:Sheep; D013480:Superovulation / Q000097:blood* / Q000378:metabolism
D000906:Antibodies; D042341:Gonadal Hormones; D012739:Gonadal Steroid Hormones; D011506:Proteins; D011994:Recombinant Proteins; C080538:attenuin; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone