Comparative developmental toxicity of di-, tri- and tetrabutyltin compounds after administration during late organogenesis in rats.

Dibutyltin dichloride (DBT), tributyltin chloride (TrBT) and tetrabutyltin (TeBT) were compared for their developmental toxicity and teratogenic potential following administration during the susceptible period for teratogenesis of TrBT. Pregnant rats were given either DBT or TrBT at a dose of 165 or 330 mumol kg-1 or TrBT at a dose of 330, 660, 1320, 2640 or 5280 mumol kg-1 on days 13-15 of pregnancy. Treatment with DBT at 165 and 330 mumol kg-1 caused a significant decrease in the maternal body weight gain. A significant decrease in the fetal weight occurred at 165 and 330 mumol kg-1. No significantly increased incidences of postimplantation loss or of fetuses with malformations were found following treatment with DBT. Treatment with TrBT at 165 and 330 mumol kg-1 resulted in a significant decrease in the maternal weight gain. A significant decrease in the fetal weight was found at 330 mumol kg-1. A significantly and markedly increased incidence of fetuses with cleft palate was noted in both groups treated with TrBT. Treatment with TeBT caused a significantly decreased maternal body weight gain at doses of 660 mumol kg-1 and above. A significantly increased incidence of fetuses with cleft palate was observed at a dose of 5280 mumol kg-1. It could be concluded that there is a difference in the manifestation and degree of developmental toxicity between DBT, TrBT and TeBT.