In vitro and in vivo antiestrogenic effects of polycyclic musks in zebrafish.
The polycyclic musks 6-acetyl-1,1,2,4,4,7-hexamethyltetraline (AHTN) and 1,2,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyran (HHCB) are used as fragrance ingredients in perfumes, soaps, and household cleaning products. They are known to be ubiquitously present in the aquatic environment, and because of their lipophilic nature, they tend to bioaccumulate in aquatic biota. In surface waters, concentrations between 1 ng/L and 5 microg/L have been found, depending mainly on the proportion of sewage effluents in the water. In fish, under normal environmental conditions, concentrations in the microgram per kilogram fresh weight (fw) range are found. In a previous study we showed that AHTN and HHCB exert mainly antiestrogenic effects on the human estrogen receptor alpha (ERalpha) and ERbeta in an in vitro reporter gene assay. In the current study, we assessed the in vitro antiestrogenic effects of both musks on zebrafish ERs. Antagonism was observed on zfERbeta, and more pronounced on the newly cloned zfERgamma. Using a transgenic zebrafish assay, we studied antiestrogenicity of the musks in vivo. Dose-dependent antagonistic effects were observed at concentrations of 0.1 and 1 microM AHTN and HHCB. GC-MS analysis showed that the musks bioaccumulated in the fish, with internal concentrations (15-150 mg/kg fw) which were roughly 600 times higher than the nominal test doses. To our knowledge, this is the first time that environmental contaminants are shown to be antiestrogenic in an in vivo fish assay that focuses solely on ER-mediated effects. This makes the transgenic zebrafish assay a promising tool for the rapid detection of both estrogenic and antiestrogenic effects of chemicals in fish.
Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80176, 3508 TD, Utrecht, The Netherlands. r.schreurs@iras.uu.nl
Richard H M M
RH
Schreurs
Juliette
J
Legler
Elsa
E
Artola-Garicano
Theo L
TL
Sinnige
Peter H
PH
Lanser
Willem
W
Seinen
Bart
B
Van der Burg
D000818:Animals; D030801:Animals, Genetically Modified; D001578:Benzopyrans / Q000493:pharmacokinetics* / Q000633:toxicity*; D001835:Body Weight; D018929:Cell Culture Techniques; D004305:Dose-Response Relationship, Drug; D004703:Endocrine System / Q000187:drug effects; D020847:Estrogen Receptor Modulators / Q000633:toxicity*; D005260:Female; D008297:Male; D010476:Perfume; D011960:Receptors, Estrogen / Q000187:drug effects*; D013764:Tetrahydronaphthalenes / Q000493:pharmacokinetics / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics / Q000633:toxicity*; D015027:Zebrafish / Q000502:physiology
D001578:Benzopyrans; D020847:Estrogen Receptor Modulators; D010476:Perfume; D011960:Receptors, Estrogen; D013764:Tetrahydronaphthalenes; D014874:Water Pollutants, Chemical; C033119:galaxolide; C033116:acetyl methyl tetramethyl tetralin