Species and strain comparison of acute neurotoxic effects of trimethyltin in mice and rats.

Pathological changes in the central nervous system in two strains of mice (BALB/c and C57BL/6) and two strains of rats (Long Evans and Sprague Dawley) as a result of trimethyltin (TMT) intoxication were compared. Both strains of mice were administered with trimethyltin chloride at a dosage of 3.0 mg TMT-Cl/kg b.w. while both strains of rats were exposed to 7.5 mg TMT-Cl/kg b.w. Animals were sacrificed at the time of development of observable neurological signs (tremor, aggression): 2 days for both strains of mice, 3 days for Long Evans (LE) rats, and 5 days for Sprague Dawley (SD) rats. It was found that there were both species and strain differences in TMT toxicity. Despite being exposed to a lower dose of TMT and for a shorter duration of time, mice showed more prominent neurological signs and hippocampal lesions than rats. Among the two strains of rats studied, LE rats were more sensitive than SD rats to TMT toxicity. The regional sensitivity of the CNS between mice and rats was also different, with mice showing most lesions in the hippocampal fascia dentata and rats showing more prominent neuronal damages in the olfactory cortices and hippocampal Ammon's horn. Our present investigation provides the first species/strain comparison on lesion development as a result of TMT intoxication.