Low-dose perinatal exposure to di(2-ethylhexyl) phthalate induces anti-androgenic effects in male rats

Perinatal di(2-ethylhexyl) phthalate (DEHP) exposure was examined in time-mated Wistar rats gavaged from gestation day 7 to postnatal day 16 with doses from 3 to 900 mg/kg-d. These doses covered the whole dose response curve for the demasculinizing effects of DEHP including low-dose effects. At a relatively low dose of 10 mg/kg-d, DEHP caused adverse anti-androgenic effects on male rat development as male anogenital distance was decreased, the incidence of nipple retention was increased, weight of levator ani/bulbocavernosus muscles and prostate was reduced and mild external genitalia dysgenesis was observed. Higher doses of DEHP induced histopathological effects on the testes, reduced testis weight, and expression of androgen-regulated genes in the prostate. The results provide new evidence of low-dose effects of DEHP and are consistent with the EU NOAEL of 5 mg/kg for DEHP. Our results also indicate a reason for concern about human exposure to DEHP. (C) 2010 Elsevier Inc. All rights reserved.