The relationship between the length of the alkyl chain of dialkyltin compounds and their effects on thymus and bile ducts in mice.

The effects on thymus and bile ducts have been studied in male mice 4 days after intravenous administration of 15 and 20 mumol/kg of di-n-butyltin dichloride, di-n-pentylin dichloride, di-n-hexyltin dichloride, di-n-heptyltin dichloride and di-n-octyltin dichloride. The degree of the reduction of relative thymus weight and thymocyte count is not dependent on the length of the alkyl chain of the di-n-alkyltin dichlorides (4 to 8 C atoms). Signs of bile duct lesions (increase of the serum alkaline phosphatase activity and bilirubin concentration, enlargement of bile duct diameter, histopathological findings) were induced only after administration of di-n-alkyltin dichlorides with alkyl chains of 4 to 6 C atoms. The toxic effects of the di-n-alkyltin compounds on thymus and bile ducts seem to be independent of each other. The investigated dialkyltin derivates exert cytotoxic effects on macrophages from spleen fragments of guinea pigs in concentrations of 10(-6) to 10(-4) M. There is a tendency toward a decrease of the cytotoxicity with the increasing length of the alkyl chains.