title: Androgens stimulate gonadotropin-II beta-subunit in eel pituitary cells in vitro.
abstract: Primary cultures of juvenile eel (Anguilla anguilla) pituitary cells were used to study the direct effects of sex steroids on gonadotropin (GtH-II) cell content and release (radioimmunoassay) as well as on mRNAs levels for alpha and GtH-II beta-subunits (dot-blot). Testosterone stimulated GtH-II production in a dose- and time-dependent manner by selectively increasing mRNAs for GtH-II beta-subunit but not alpha-subunit. This positive effect was also induced by non-aromatizable androgens (androstanediol and dihydrotestosterone) but not by estradiol, indicating an androgen-specific effect in the eel. The androgen-specific stimulation of eel GtH-II beta appears closer to the regulation of mammalian follicle stimulating hormone-beta (FSHbeta) than that of salmonid GtH-II beta or mammalian luteinizing hormone-beta (LHbeta)-subunits. Comparison with previous in vivo experiments suggests multiple sites of action of sex steroids on the brain-pituitary gonadotropic axis for the positive feedback on GtH-II synthesis in this juvenile fish.
authors.affiliation: Laboratoire de Physiologie Générale et Compareé, Muséum National d'Histoire Naturelle, URA 90 CNRS, Paris, France.
authors.forename: Y S
authors.initials: YS
authors.lastname: Huang
authors.forename: M
authors.initials: M
authors.lastname: Schmitz
authors.forename: N
authors.initials: N
authors.lastname: Le Belle
authors.forename: C F
authors.initials: CF
authors.lastname: Chang
authors.forename: B
authors.initials: B
authors.lastname: Quérat
authors.forename: S
authors.initials: S
authors.lastname: Dufour
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000811:Anguilla / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000235:genetics; D037201:Follicle Stimulating Hormone, beta Subunit; D006065:Gonadotropins, Pituitary / Q000235:genetics*; D007700:Kinetics; D007986:Luteinizing Hormone / Q000235:genetics; D010902:Pituitary Gland / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D013739:Testosterone / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000728:Androgens; D037201:Follicle Stimulating Hormone, beta Subunit; D006065:Gonadotropins, Pituitary; D012333:RNA, Messenger; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone