The effect of the aromatase inhibitor fadrozole and two polynuclear aromatic hydrocarbons on sex steroid secretion by ovarian follicles of coho salmon.
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 incubated in vitro with various concentrations of testosterone (0.10-0.40 microM) and fadrozole (10 and 100 microM), or with varying doses (between 0.05 and 5.0 microM) of the PAHs beta-naphthoflavone (BNF) and 20-methylcholanthrene (20-MC). 17 beta-Estradiol secretion was significantly reduced when follicles were incubated in the presence of fadrozole, BNF, or 20-MC. In contrast, 17 beta-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 17 beta-estradiol production no effect on testosterone secretion was observed. Hence, both fadrozole and PAHs can significantly reduce 17 beta-estradiol secretion by salmon ovarian follicles and may affect female sexual development.
Afonso
L O
LO
West Vancouver Laboratory, Fisheries and Oceans Canada, West Vancouver, BC, Canada.
Campbell
P M
PM
Iwama
G K
GK
Devlin
R H
RH
Donaldson
E M
EM
D000818:Animals; D047072:Aromatase Inhibitors; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology; D017316:Fadrozole / Q000494:pharmacology*; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism*; D008748:Methylcholanthrene / Q000494:pharmacology; D017684:Oncorhynchus kisutch / Q000378:metabolism*; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000494:pharmacology*; D019324:beta-Naphthoflavone / Q000494:pharmacology
D047072:Aromatase Inhibitors; D004791:Enzyme Inhibitors; D012739:Gonadal Steroid Hormones; D011084:Polycyclic Aromatic Hydrocarbons; D004958:Estradiol; D008748:Methylcholanthrene; D019324:beta-Naphthoflavone; D017316:Fadrozole