PARACELLULAR TRANSPORT-PROPERTIES OF INNER-EAR BARRIERS DO NOT ACCOUNT FOR CISPLATIN TOXICITY IN THE RAT

The interindividual variability for the ototoxic effect of the antineo plastic drug cisplatin has still to be explained. To examine if the va riability can be related to differences in drug kinetics, the effect o f cisplatin on the paracellular transport properties of the inner ear barriers was studied in vivo in cisplatin treated Long-Evans rats. The concentration of [H-3]mannitol was followed in plasma, scala vestibul i perilymph, and endolymph after an intravenous infusion of the tracer . Cisplatin had no effect on paracellular transport of the inner ear b arriers 3 days after administration of 8 mg/kg cisplatin. However, an interindividual variability for the transport of [H-3]mannitol across the blood-perilymph barrier was evident, indicating a Variability for the passive transport of solutes to the inner ear.