Synthetic human seminal alpha-inhibin-92 selectively suppresses follicle-stimulating hormone release in vivo.
A 92-amino acid polypeptide, alpha-inhibin-92 (alpha-IB-92), has been isolated and characterized from human seminal plasma and found to be active in suppressing follicle-stimulating hormone (FSH) release in vitro. In the present in vivo study, intravenous injection of synthetic alpha-IB-92 (4 and 20 micrograms) significantly suppressed FSH release (P less than 0.001), whereas this peptide had no effect on luteinizing hormone (LH) release in 1-day orchidectomized male rats. In contrast, third ventricular injection of alpha-IB-92 (0.02, 0.4, 4, or 20 micrograms) had no effect on FSH and LH release in 1- or 2-day orchidectomized rats. These results indicate that alpha-IB-92 exerts a FSH suppressing activity by direct action on the pituitary gland.
D000818:Animals; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007265:Inhibins / Q000008:administration & dosage / Q000494:pharmacology*; D007275:Injections, Intravenous; D007276:Injections, Intraventricular; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D009919:Orchiectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012661:Semen / Q000502:physiology*
D007987:Gonadotropin-Releasing Hormone; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C051562:alpha-inhibin-92