Androgens stimulate gonadotropin-II beta-subunit in eel pituitary cells in vitro.
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.
Huang
Y S
YS
Laboratoire de Physiologie Générale et Compareé, Muséum National d'Histoire Naturelle, URA 90 CNRS, Paris, France.
Schmitz
M
M
Le Belle
N
N
Chang
C F
CF
Quérat
B
B
Dufour
S
S
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
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