Dieldrin, estrogenic activity

Ramamoorthy K, Wang F, Chen I-C, et al. 1997. Estrogenic activity of a dieldrin/toxaphene mixture in the mouse uterus, MCF-7 human breast cancer cells, and yeast-based estrogen receptor assays No apparent synergism. Endocrinology 138(4) 1520-1527. 

Gellert RJ. 1978. Kepone, mirex, dieldrin, and aldrin Estrogenic activity and the induction of persistent vaginal estrus and anovulation in rats following neonatal treatment. Environ Res 16 131-138. 

Over the last decades, large amounts of different man-made chemicals which can act as weak estrogens have been released into the terrestrial and aquatic environment and are distributed world-wide. Classical environmental estrogens are pesticides, such as o,p -DDT, and its metabohtes o,p -DDE and o,p -DDD, methoxychlor and its metabolites, chlordecone (Kepone ), dieldrin, Toxaphene, and endosulfan [126, 135, 136]. It is also known that many chemicals with very weak or no measurable estrogenic activity can be metabolized in organisms especially to hydroxylated compounds which may have much more estrogenic potency than the parent compound. Examples are methoxychlor and its mono- and di-demethylated derivatives [126,127] as well as the alkylphenol... 

The test system was considerably less sensitive to endosulfan when mouse ER, rather than human ER, was used to mediate (3-gal activity (Ramamoorthy et al. 1997). In similar assays, endosulfan at 10 jM had no effect on (3-gal activity in yeast Saccharomyces) transfected with either the human or rainbow trout ER (Andersen et al. 1999). In addition, no effect was observed on transcriptional activation of HeLa cells transfected with plasmids containing an estrogen receptor as a responsive element (Shelby et al. 1996). Endosulfan also did not induce transient reporter gene expression in MCF-7 human breast cancer cells at an incubation concentration of 2.5 pM (Andersen et al. 1999). Maximum endosulfan-induced ER-mediated luciferase reporter gene expression occurred in vitro in a T47D human breast adenocarcinoma cell line at approximately 10 pM, while 50% expression of luciferase occurred at about 5.9 pM the maximum expression was approximately 59% of the effect from exposure to 0.03 nM estradiol (0.00003 pM) (Legler et al. 1999). Luciferase expression from combined treatment with endosulfan and dieldrin was additive over concentrations ranging from 3 to 8 pM. 

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