Toxaphene 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. 

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... 

It is also known that Toxaphene has low estrogenic activity. However, it is not clear which compounds of the mixture are responsible for this effect. With the pure single chlorinated bornane congeners this is now also possible. It is assumed that some hydroxylated chlorinated bornane metabolites and/or keto metabolites may be responsible for the estrogenic activity. 

The estrogenic activity of toxaphene and synergetic transactivation caused by other organochlorines according to Arnold et al. [249], have been discussed controversially [250-252]. The answer to this question is of central importance, since toxaphene itself is a multicomponent mixture If there is a synergetic potential, it is important to know which congeners have endocrine effects and whether or not there are synergetic effects between the compounds present in technical toxaphene. Because of these unsolved problems, a detailed discussion of this phenomenon is not possible at the moment. 

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