ENVIRONMENTAL SIGNALING - A BIOLOGICAL CONTEXT FOR ENDOCRINE DISRUPTION

Endogenous and exogenous chemical signals have evolved as a means for organisms to respond to physical or biological stimuli in the environm ent. Sensitivity to these signals can make organisms vulnerable to ina dvertent signals from xenobiotics. in this review we discuss how vario us chemicals can interact with steroidlike signaling pathways, especia lly estrogen. Numerous compounds have estrogenic activity, including s teroids, phytoestrogens, and synthetic chemicals. We compare bioavaila bility, metabolism, interaction with receptors, and interaction with c ell-signaling pathways among these three structurally diverse groups i n order to understand how these chemicals influence physiological resp onses. Based on their mechanisms of action, chemical steroid mimics co uld plausibly be associated with recent adverse health trends in human s and animals.