Adverse effects of diisooctyl phthalate on the male rat reproductive development following prenatal exposure

In a first study, rats were given diisooctyl phthalate (DIOP, CAS 27554-26-3) at 0, 0.1, 0.5, and 1 g/kg/day, by gavage, on gestation days 6 through 20 (GD). There was a significant increase in resorptions at 1 g/kg/day and a reduction in fetal weights at 0.5 and 1 g/kg/day. Undescended testes were observed in fetuses at 1 g/kg/day, and supernumerary lumbar ribs and ossification delay at 0.5 and 1 g/kg/day. In a follow-up study, DIOP administered on GD 12 to 19 reduced fetal testicular testosterone at 0.1 g/kg/day and above. Finally, postnatal reproductive assessment was conducted in adult male offspring prenatally exposed to DIOP on GD 12 to 21. Abnormalities of reproductive system (e.g. hypospadias, non scrotal testes, and hypospermatogenesis) were observed in a few adult males at 0.5 g/kg/day, and with a high incidence at 1 g/kg/day. Thus, DIOP displayed an antiandrogenic activity and disrupted the male reproductive development