Direct and indirect assessment of the aneuploidy-inducing potency of organotin compounds

By Jensen, K.G. - Andersen, O. - Ronne, M.

The spindle-inhibiting and aneuploidy-inducing potency of in vitro exposure of PHA-stimulated human lymphocytes to organotin compounds has been studied indirectly by quantitation of chromosomal contraction and directly by determination of the frequency of aneuploidy by chromosome counting. The effects of trimethyltin chloride (TMT), dimethyltin chloride (DMT), tributyltin chloride (TBT), dibutyltin chloride (DBT), triphenyltin chloride (TPhT), and diphenyltin chloride (DPhT) on chromosal contraction were studied at concentrations of 10(-3)-10(-9)M, by measurement of the average length of chromosome 1 from asynchronous cultures of human peripheral lymphocytes. TMT, TBT, TPhT and DPhT appear to be very strong inducers of chromosomal supercontraction, indicating that these compounds are possible spindle inhibitors, while DMT and DBT seem to be ineffective. TMT, TBT, TPhT and DPhT gave rise to a little more than 100% increase in the number of hyperdiploid cells, all the increases being statistically significant except for that induced by TBT, indicating that organotin compounds are capable of inducing aneuploidy, probably by affecting spindle function.