In vitro studies on the embryotoxic potential of (bis[tri-n-butyltin])oxide in a limb bud organ culture system.

(Bis[tri-n-butyltin])oxide (TBTO) was studied for its toxic potential on prenatal development. The effect of this substance on limb differentiation (mouse embryos) in organ culture was evaluated. In the organ culture system using mouse limb buds, TBTO interfered with morphogenetic differentiation at doses as low as 0.03 microgram/ml (5 X 10(-8)M). This is one of the lowest concentrations of a substance ever found to be active in this in vitro system. The in vitro studies suggest a high embryotoxic potential of TBTO. The low embryotoxicity found in the in vivo studies may be due to limited exposure of the embryos by the original unmetabolized substance.