Teratogenicity study of tri-n-butyltin acetate in rats by oral administration.

A teratological test was carried out on tri-n-butyltin acetate (TBTA) used as a biocide and anti-fouling agent. Pregnant Wistar rats were treated orally with TBTA at dose levels of 0, 1, 2, 4, 8, and 16 mg/kg from days 7-17 of gestation. Cesarean sections were performed on day 20 of gestation. In pregnant rats, salivation and depression of body weight gain and food intake were observed at a late stage of pregnancy at the highest dose level of TBTA. Atrophy of the thymus was also observed in a dose-dependent manner on day 20 of gestation. In the fetuses, treatment with the highest dose level increased embryonic and fetal deaths, increased the incidence of fetuses with cleft palate, cervical rib and/or rudimentary lumbar rib, and decreased the body weights of fetuses.