Developmental and behavioral effects of early postnatal exposure to triethyltin in rats.

On Day 5 of postnatal life, rat pups received a single injection of triethyltin and were later tested for a variety of developmental and adult behaviors. A within-litter dosing design was used with one male and one female from each litter (N = 8 pups/litter) receiving either 0 (normal saline vehicle), 3, 6 or a high dose of either 9 or 12 mg/kg triethyltin bromide (TET). The high doses of TET produced 50% and 80% mortality, respectively. For the 3 and 6 mg/kg groups, TET-exposure resulted in a transient decrease in body weight, and a permanent decrease in brain weight. Preweaning TET-exposed pups were less successful in descending a rope, and were less active in both a homing orientation test and a figure-eight maze. When tested as adults, however, these animals were consistently more active than controls in the figure-eight maze. These results indicate that a single exposure to TET in ;the developing rat, unlike the adult, produces permanent alterations in both brain and behavior. Acute postnatal exposure to toxicants may have general applicability as a model for developmental neurotoxicity.