Endocrine disruption defined

P. P. Lopez-Casa, S. C. Mizrak, L. A. Lopez-Fernandez, M. Paz, D. G. de Rooij and J. Del Mazo, The effects of different endocrine disrupters defining compound-specific alterations of gene expression profiles in the developing testes, Reprod. Toxicol., 2012, 33, 106-115. 

It was agreed at the workshop that endocrine disrupting activity could only be adequately defined in terms of effects in intact animals, be they juvenile or adult, or in the offspring of exposed parents. For many chemicals, evidence of endocrine disrupting activity has been obtained only by the use of in vitro models, such as hormone binding assays. It was accepted, therefore, that chemicals active in such models should be considered only as potential EDs and should be distinguished from those established as active in vivo. For such chemicals, an alternative definition was recommended ... 

The main conclusion of an expert workshop on endocrine modulators and wildlife in 1997 was that some existing test methods, as defined in guidelines published by the Organization for Economic Cooperation and Development (OECD), could be adapted to incorporate specific endocrine disrupting endpoints, but that there might also be the need to develop new tests, e.g. for fish. On behalf of the UK Government, the MRC Institute for Environment and Health (lEH)... 

Female sexual development and behaviour in mammals occurs by default and requires no ovarian secretion, and it is only in genetic males that the testis can secrete hormones which destroy this female pattern and superimpose that of the male. Sexual differentiation is not so well defined in fish, and larval exposure to both synthetic estrogens and androgens is widely used in aquaculture to produce monosex cultures. Endocrine disruption of sexual differentiation in fish may therefore reflect both the complexity and diversity of such processes between different species. Some care is required in use of the terms hermaphrodite and sex-reversal since a true hermaphrodite has both functional testes and ovaries and a sex-reversed fish is fully functional as its final sex—both produce the appropriate viable gametes. Such functional sex-reversal is not possible in mammals, but in some species of fish it is the normal developmental pattern. In most of the cases of hermaphroditism or sex-reversal reported in the non-scientific press, there is evidence only for a few ovarian follicles within a functional testis. This may be considered as feminisation or a form of intersex, and is very clearly endocrine disruption, but it is certainly neither sex-reversal nor hermaphroditism. In some cases the terms have even been used to infer induction of a single female characteristic such as production of yolk-protein by males. 

The Danish List of Undesirable Substances is a list of chemicals of concern that the government believes should be avoided to the extent feasible in commerce. Using a systematic analysis, substances are selected automatically if they meet some clear and defined criteria, for example, problematic classifications, because they are imder suspicion for being PBT/vPvB (Persistent, Bioaccumulative, Toxic/very Persistent, very Bio accumulative) or endocrine-disrupting. 

In the OECD Draft Guidance Document on Reproductive Toxicity Testing and Assessment (OECD 2004d), the term endocrine disruption is defined as above. 

Definition of the U.S. Environmental Protection Agency [101] An environmental endocrine disrupter is defined as an exogenous agent that interferes with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body, that are responsible for the maintenance of homeostasis, reproduction, development, and/or behavior. 

In the past few years, considerable attention has been given to the presence of endocrine disrupting compounds (EDC) in the aquatic environment. EDC ate not defined by chemical nature but rather by their biological effect. The endocrine system is an intricate hormone system that regulates development, growth, reproduction, and behaviour [1-2]. The two relevant classes of compounds that can... 

The World Health Organization defines endocrine-disrupting compounds (EDCs) as exogenous substances that alter function(s) or the endocrine system and consequently cause adverse health effects in an intact organism, or its progeny or (sub)-populations. I13l Endocrine disrup-tors can act in any of four different waysJ14 These are... 

Endocrine disruption has been defined as an exogenous chemical substance or mixture that alters the structure or function(s) of the endocrine system and causes adverse effects at the level of the... 

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