Developmental effects of trimethyltin intoxication in the neonatal mouse. I. Light microscopic studies.

The effects of trimethyltin (TMT) intoxication on the developing mouse brain were studied. BALB/c mice were injected intraperitoneally with 3.0 mg TMT/kg body weight on postnatal day 3. Animals were sacrificed at selected intervals to 30 days of age and their brains examined by light microscopy. Increased eosinophilia and granularity of hippocampal pyramidal neurons and neurons of the pyriform cortex were detected as early as 16 hours post-administration. Extensive degenerative and necrotic charges were observed 1 to 10 days post-administration, particularly in hippocampal region CA-3 of Ammon's horn. Cerebellar Purkinje and granule neurons, basal ganglia and cerebral cortex were involved to a lesser extent. Pathological changes of granule cells in the fascia dentata were much less extensive than reported in adult mice. Astrogliosis was occasionally pronounced. Distribution of lesions within the hippocampus indicate that acute neonatal TMT exposure results in a different regional pattern of injury than in acutely treated adult mice.