Prenatal and postnatal exposure to low levels of permethrin exerts reproductive effects in male mice.

Permethrin, a pyrethroid chemical, is widely used as a pesticide because of its rapid insecticidal activity. Although permethrin is considered to exert very low toxicity on mammalian reproductive organs, the effects of early low-level and chronic exposure on adult spermatogenesis are unclear. We exposed mice to environmentally relevant concentrations of permethrin (0, 0.3, and 30ppm) in drinking water during prenatal and postnatal period and examined the effects on the testis in mice offspring when they reached maturity (12 weeks of age). Using methyl green-pyronin staining, we found an abnormal accumulation of RNA in the seminiferous epithelia of mice treated with permethrin; this accumulation may be derived from an enlargement of the residual body. Additionally, permethrin may cause a decline of Sertoli cell functions. Our findings demonstrate that low-level and chronic permethrin exposure during prenatal and postnatal period has distinct effects on male reproductive system in mice.