The mechanisms of action of reproductive toxins.

A general discussion of the mechanisms of action of reproductive toxins is presented. Reproductive toxicants may produce their adverse effects by one of several mechanisms. Some xenobiotics may act directly, either by virtue of chemical reactivity (eg, oocyte destruction by alkylating agents) or by structural similarity to endogenous molecules (eg, hormone antagonists). Other xenobiotics interrupt reproductive processes indirectly either by metabolic processing to a direct-acting toxicant (eg, prohormone or metabolic activation to reactive intermediate) or by altering endocrine homeostasis (eg, increased steroid clearance). Selected examples of compounds demonstrating reproductive toxicity by one or more of these mechanisms are tabulated and an extensive bibliography of reproductive toxins is attached.