Stress proteins in reproductive toxicology.

Although a wide range of physical and chemical agents disrupt gametogenesis and embryogenesis in animals and humans, much less is known about the mechanisms leading up to these disruptions and the factors that determine whether a particular animal or human will be sensitive to a potential toxicant. Recent research has identified a number of different stress protein families, also known as heat shock proteins (HSPs), that play a role in protecting cells and organs from the toxic effects of exposure to hyperthermia and chemical insult (1). These stress proteins could provide significant insight into cellular processes susceptible to toxicant action and the mechanisms that have evolved to protect them. Understanding these protective mechanisms will allow more accurate extrapolation of animal data to humans and thereby improve the assessment of human health risk for a potentially broad range of reproductive and developmental toxicants. To explore the role of stress proteins in reproductive toxicology, the Reproductive Toxicology Division of the National Health and Environmental Effects Research Laboratory of the U.S. Environmental Protection Agency (EPA) held a mini-workshop on 1 November 1996 in Research Triangle Park, North Carolina. Seven intramural and extramural scientists (see shaded box), experts in the field of HSPs, presented findings from their respective laboratories and participated in a roundtable discussion of research issues significant to the workshop theme. The research and its implications for toxicology are summarized here. This information promises to provide insights into toxicological processes modulated by HSPs. Furthermore, this research will advance the EPA's long-term goal to develop a scientific basis for assessing and characterizing risks to human health.