Due to the time and expense associated with full life-cycle testing, most current toxicity tests with fish do not explicitly consider reproductive output as an endpoint but, rather, focus on early life-stage survival and development. However, some classes of chemicals could adversely impact reproduction at concentrations below those that affect development. Further, estimates of the effects of ...

The pesticide methoxychlor (MXC) is a reproductive toxicant that targets antral follicles of the mammalian ovary. Cytochrome P450 enzymes metabolize MXC to mono-OH MXC (1,1,1-trichloro-2-(4-hydroxyphenyl)-2-(4-methoxyphenyl)ethane [mono-OH]) and bis-OH MXC (1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane [HPTE]), two compounds that are proposed to be more toxic than the parent compound, can inte...

A growing number of environmental toxicants found in pesticides, herbicides, and industrial solvents are believed to have deleterious effects on development by disrupting hormone-sensitive processes. We exposed Xenopus laevis embryos at early gastrula to the commonly encountered environmental estrogens nonylphenol, octylphenol, and methoxychlor, the antiandrogen, p,p-DDE, or the synthetic andro...