Behavioral effects of trimethyltin in two strains of mice. I. Spontaneous motor activity

Adult male mice (C57BL/6N and BALB/c) were administered single doses of trimethyltin X Cl (TMT) by the ip route. The effects of TMT administration were determined on lethality (3-6 mg/kg), spontaneous motor activity (SMA), and the physical appearance of the mice (0.3-3 mg/kg). The effects of TMT on lethality were strain dependent in that a single dose of 3 mg/kg, ip, produced approximately 35% lethality in the C57BL/6N strain during the first 72 hr following administration. Less than 15% lethality was observed at this dose in the BALB/c strain. In both strains, 3.5 mg/kg, ip, produced more than 70% lethality during the first 144 hr after administration. Higher doses produced proportionally greater lethality. The SMA of both strains was not affected significantly at doses below 1 mg/kg, ip. At 1 mg/kg a small decrease in activity was observed during the first 24 hr. At 3 mg/kg, SMA was initially decreased in both strains. However, the decrease was of smaller magnitude in the C57BL strain and was followed by a large increase in SMA which did not return to control levels for approximately 1 week. An increase in SMA was observed in the BALB/c strain on the fifth day following TMT but returned to control values by Day 6. At 3 mg/kg, ip, the C57BL mice were observed to have severe whole body tremors and were hypersensitive to external stimuli. The whole body tremor was not as marked in the BALB/c strain. Neuropathological studies on the treated mice indicated that the behavioral studies paralleled the pathology produced by TMT. These data confirm the initial observation of greater sensitivity of the mouse to toxic effects of TMT compared to the rat.