Biology Reference
In-Depth Information
8
Impairments of Endocrine Functions:
Causes an
d Consequences
Jean-Claude Amiard, Arnaud Chaumot, Mickaël Couderc,
Jeanne Garric, Olivier Geffard, and Benoît Xuereb
CONTENTS
8.1 Introduction ........................................................................................................................ 187
8.2 Generalities ......................................................................................................................... 189
8.2.1 Normal Mechanisms of Hormonal Action ........................................................ 189
8.2.2 Mechanisms of Endocrine Disruption: Principle of Lock and Key ................ 190
8.2.2.1 Mechanisms of Disruption .................................................................... 190
8.2.2.2 What Are Endocrine Disruptors? ......................................................... 191
8.3 Effects of EDCs on Reproductive System ....................................................................... 192
8.3.1 Estrogenic Activities .............................................................................................. 192
8.3.2 Antiestrogenic Activities ...................................................................................... 193
8.3.3 Effects of Complex Mixtures Containing Substances with Endocrine
Potential ................................................................................................................... 194
8.4 Thyroid Endocrine Disruptors ......................................................................................... 195
8.5 Impairment of Endocrine Functions in Crustaceans ................................................... 199
8.5.1 Endocrine Regulation of Reproduction in Crustaceans .................................. 199
8.5.2 Impact of EDCs on Crustaceans .......................................................................... 200
8.5.3 Tools for Monitoring Crustacean Exposure to EDCs ....................................... 201
8.6 Endocrine Control and Disruption in Mollusks ........................................................... 203
8.7 Ecological Consequences of Endocrine Disruption ...................................................... 204
8.8 Conclusions ......................................................................................................................... 206
References ..................................................................................................................................... 207
8.1 Introduction
The problem of endocrine disruptor compounds (EDCs) became apparent with observa-
tions in the field of major noxious effects such as the thinning of egg shells of certain birds
(due to dichlorodiphenyltrichloroethane, DDT), the appearance of a penis (imposex) in
female marine gastropods [due to tributyltin (TBT); cf. Chapter 9], and reports of reproduc-
tive disorders in seals from the Baltic [exposed to polychlorobiphenyl (PCBs), to DDT and
their metabolites], these various disturbances ending in a drastic reduction of the popula-
tions concerned. Historically, reports of abnormal sexual development in reptiles (Guillette
et al. 1994, 1995) or birds (Fry 1995), as well as feminization responses in male fish (Jobling
and Sumpter 1993; White et al. 1994; Jobling et al. 1995), have suggested an endocrine
187
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