Environmental estrogens interact with and modulate the properties of plasma sex steroid-binding proteins in juvenile Atlantic salmon (Salmo salar).
Environmental chemicals may modulate the endocrine system through interaction with plasma sex steroid-binding proteins (SBP) and SBP-regulated processes. Some of these chemicals, which are known to interact with the estrogen receptor (ER), were found to bind competitively to the Atlantic salmon (Salmo salar) SBP and potentially disrupt the endocrine function of these proteins. Furthermore, both weakly acting (di-n-butyl phthalate) and potent estrogen mimics (ethynylestradiol), were able to induce a substantial up-regulation of circulating levels of SBP in vivo. Interestingly, modulation of SBP-levels was found to be a more sensitive endpoint than chemically induced interference with classical ER-mediated mechanisms for weakly acting estrogen mimics like di-(n-butyl) phthalate. Interference with the endocrine function of SBPs may thus introduce a novel mechanism for endocrine disruption. and give additional answers to the question why some weakly acting xenoestrogens are causing "estrogen-like" reproductive disturbances in developing males.
Tollefsen
Knut-Erik
KE
Department of Biology, University of Oslo, Norway. knut.erik.tollefsen@niva.no
Meys
Joris F A
JF
Frydenlund
Jorid
J
Stenersen
Jørgen
J
D000818:Animals; D003993:Dibutyl Phthalate / Q000009:adverse effects*; D004703:Endocrine System / Q000187:drug effects; D045166:Estradiol Congeners / Q000009:adverse effects*; D004997:Ethinyl Estradiol / Q000009:adverse effects*; D005260:Female; D008297:Male; D011960:Receptors, Estrogen / Q000096:biosynthesis* / Q000187:drug effects; D020317:Salmo salar / Q000502:physiology*; D012738:Sex Hormone-Binding Globulin / Q000096:biosynthesis*; D015854:Up-Regulation; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
D045166:Estradiol Congeners; D011960:Receptors, Estrogen; D012738:Sex Hormone-Binding Globulin; D014874:Water Pollutants, Chemical; D003993:Dibutyl Phthalate; D004997:Ethinyl Estradiol