Behavioral effects of acute exposure to tributyltin chloride in rats

The behavioral effects of a single acute exposure to nonlethal doses of tributyltin chloride (TBTCl) were studied in male Wistar rats. The rats were given TBTCl by oral gavage at doses of 0, 6.3, 12.5, 25.0 or 50.0 mg/kg, and spontaneous motor activity (SMA) and acquisition of conditioned avoidance responses in a shuttle box were monitored. Body weight gain in the 50.0-mg/kg group was significantly lowered, but weight gain in the 6.3-, 12.5- and 25.0-mg/kg groups was comparable to that in the control group. TBTCl caused a dose-related decrease in SMA during the dark phase. The 24-h total daily and 12-h nocturnal activity was decreased at doses of 12.5 mg/kg and above. The acquisition of shock avoidance responses was inhibited in all TBTCl-treated groups in a dose-dependent manner, and the difference was significant for rats given TBTCl at doses of 25.0 mg/kg and above. The data indicate that an acute exposure to TBTCl can cause significant changes in rat behavior and suggest that SMA can serve as a sensitive index for detecting its toxicity.