trabalho

REVISTA BRASILEIRA
DE TOXICOLOGIA
BRAZILIAN JOURNAL
OF TOXICOLOGY

Revista Brasileira de Toxicologia 21, n.1 (2008) 1 - 8

Exposição ambiental a desreguladores endócrinos: alterações na homeostase dos hormônios esteroidais e tireoideanos
Natália V. Moraes, Marcella D. Grando, Daniel A. R. Valerio, Danielle P. Oliveira*
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto,
Universidade de São Paulo, Ribeirão Preto, SP, Brasil

Abstract
Environmental exposure to endocrine disruptors: alterations in steroidal and thyroid hormones homeostasis
Endocrine disruptors, exogenous compounds that alter the endogenous hormone homeostasis, have been systematically discharged in the environment during the last 60 years. These contaminants have been related to the decrease of human sperm number and increased of the incidence of testicular, breast and thyroid cancer. During the same period, developmental and reproductive effects have also been documented in wildlife species. This work presents a review of the effects and mechanisms of action of steroidal and thyroid disruptors. Several studies from 1950 until 2008 were reviewed in PubMed,
ScienceDirect databases and text books. Our findings showed that endocrine disruptors can act by the following mechanisms:
i) inhibition of enzymes related to hormone synthesis; ii) alteration of free concentration of hormones by interaction with plasmatic globulins; iii) alteration in expression of hormone metabolism enzymes; iv) interaction with hormone receptors, acting as agonists or antagonists; v) alteration of signal transduction resulting from hormone action. The importance of the identification of endocrine disruptors involves characterization of environmental contaminants and inquiry of new substances discharged in the environment. The minimization of exposure and/or rationalization of the use of these compounds are related to the preservation