title: Recombinant human activin-A stimulates basal FSH and GnRH-stimulated FSH and LH release in the adult male macaque, Macaca fascicularis.
abstract: Activin-A is a homodimer of the beta A inhibin subunit that stimulates FSH secretion by pituitary cells in vitro; however, the physiological relevance of this effect is unknown. We have examined whether recombinant human activin-A (activin-A; 80 micrograms/kg/day iv infusion for 50.5 h) has in vivo bioactivity in the adult male macaque (n = 5). Serum FSH and LH bioactivity and serum testosterone (T) levels were measured on 2 control days and after 24 and 48 h of activin-A administration. Basal FSH levels increased significantly (p less than 0.05) by 17% at 24 h and 82% at 48 h during activin-A administration. No changes in basal LH or T levels were seen. The FSH and LH responses to GnRH (5 micrograms/kg, iv bolus) increased significantly (p less than 0.05) by 117% and 55% after 48 h of activin-A, respectively. A small (16%), but statistically significant (p less than 0.05), increase in the T response to the GnRH challenge was also noted. These data are preliminary evidence in support of a physiological role for activin-A in the control of gonadotropin secretion in the male primate.
authors.affiliation: Department of Medicine University of Washington, Seattle 98195.
authors.forename: R I
authors.initials: RI
authors.lastname: McLachlan
authors.forename: K D
authors.initials: KD
authors.lastname: Dahl
authors.forename: W J
authors.initials: WJ
authors.lastname: Bremner
authors.forename: R
authors.initials: R
authors.lastname: Schwall
authors.forename: C H
authors.initials: CH
authors.lastname: Schmelzer
authors.forename: A J
authors.initials: AJ
authors.lastname: Mason
authors.forename: R A
authors.initials: RA
authors.lastname: Steiner
mesh_terms: D028341:Activins; D000818:Animals; D001681:Biological Assay; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects; D006801:Humans; D007265:Inhibins / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D008252:Macaca fascicularis; D008297:Male; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology*; D012016:Reference Values
chemical_list: D011994:Recombinant Proteins; D028341:Activins; D007987:Gonadotropin-Releasing Hormone; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone