The Effect of the Aromatase Inhibitor Fadrozole and Two Polynuclear Aromatic Hydrocarbons on Sex Steroid Secretion by Ovarian Follicles of Coho Salmon

• Published in: General and comparative endocrinology 1997-05, Vol.106 (2), p.169-174
• Main Authors: Afonso, L.O.B., Campbell, P.M., Iwama, G.K., Devlin, R.H., Donaldson, E.M.
• Format: Article
• Language: English
• Subjects: Animals; Aromatase Inhibitors; beta-Naphthoflavone - pharmacology; Enzyme Inhibitors - pharmacology; Estradiol - pharmacology; Fadrozole - pharmacology; Female; Gonadal Steroid Hormones - metabolism; Methylcholanthrene - pharmacology; Oncorhynchus kisutch - metabolism; Ovarian Follicle - drug effects; Ovarian Follicle - metabolism; Polycyclic Aromatic Hydrocarbons - pharmacology
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1006/gcen.1996.6855

A variety of endogenous and exogenous factors can influence sex steroid production by salmon ovarian follicles and ultimately impact reproductive development. We examined the effect of an aromatase inhibitor, fadrozole, and common environmental contaminants (PAHs) on sex steroid secretion by ovarian follicles. Ovarian follicles of coho salmon were incubatedin vitrowith various concentrations of testosterone (0.10–0.40 μM) and fadrozole (10 and 100 μM), or with varying doses (between 0.05 and 5.0 μM) of the PAHs β-naphthoflavone (BNF) and 20-methylcholanthrene (20-MC). 17β-Estradiol secretion was significantly reduced when follicles were incubated in the presence of fadrozole, BNF, or 20-MC. In contrast, 17β-estradiol production by ovarian follicles increased in a dose-dependent manner when incubated with increasing doses of the aromatizable androgen testosterone. Although increasing doses of PAHs significantly reduced follicular 17β-estradiol production no effect on testosterone secretion was observed. Hence, both fadrozole and PAHs can significantly reduce 17β-estradiol secretion by salmon ovarian follicles and may affect female sexual development.