EFFECT OF HIGH-DOSES OF 2-CDA ON SCHWANN-CELLS OF MOUSE PERIPHERAL-NERVE

The present study was undertaken to examine the effect of 2-CdA (Leust atin) on the Schwann cells of myelinated and unmyelinated fibers of pe ripheral mouse nerve. Two groups of mice were injected intravenously f or seven days with 2-CdA: one group received daily doses of 1 mg/kg an d the other 0.5 mg/kg. Both doses exceeded those accepted in clinical practice. Mice injected with saline served as controls. The sciatic ne rve was then dissected and examined with a transmission electron micro scope. The Schwann cells of both the myelinated and unmyelinated nerve fibers of the animals receiving the higher doses of 2-CdA showed nucl ear and nucleolus damage, loss of heterochromatin, vacuolization and d isorganization of the myelin sheaths. The mesaxons and the axons were also damaged. The Schwann cells of the animals treated with the lower doses appeared undamaged. The results indicate that in contrast to oth er anticancer drugs known to produce peripheral neuropathy, 2-CdA may cause damage to the Schwann cells only at doses exceeding the therapeu tic ones.