Human exposure to endocrine disrupting chemicals as a prenatal risk factor for cryptorchidism

This review describes the most recent data on the eff ects of endocrine disrupting compounds on reproductive tract development, as well as controversies in the fi eld. One of the most frequent conditions aff ected by endocrine disrupting compounds is cryptorchidism. Recent reports regarding the cause of this disorder continue to increase our understanding of this common and important problem. Endocrine disruptors are defi ned as exogenous substances with the ability to disrupt normal endocrine homeostasis and reproduction, and they include xenoestrogens, synthetic and natural hormones, phytoand mycoestrogens, and other substances aff ecting endocrine signaling. Human exposure to endocrine disrupting chemicals is widespread. Epidemiological studies suggest associations between prenatal exposure to endocrine disrupting chemicals and numerous malformations of androgen dependent tissues. Animal models and epidemiological evidence link exposure to androgen disrupting chemicals with cryptorchidism, reduced sperm cell counts, increasing infertility, and testicular and prostate cancers. Since male sexual diff erentiation is androgen dependent, it is highly susceptible to endocrine disruptors. Whether the level of exposure contributes to the increasing prevalence of cryptorchidism is an ongoing debate. Further, there appears to be increased sensitivity to these agents during critical developmental periods when male diff erentiation is at its peak. Diff erences in the interpretation of the available studies underlie the disparate conclusions of scientifi c and regulatory body panels on the potential toxicological eff ects of endocrine disrupting chemicals at the current levels of human exposure. This review will highlight the evidence for endocrine disrupting chemicals that act through interference with the androgen receptor and lead to cryptorchidism.