Vincristine-induced alterations in Schwann cells of mouse peripheral nerve.

The sciatic nerve of C57Bl mice was examined with a transmission electron microscope to study the ultrastructural alterations in Schwann cells following treatment with escalating doses of vincristine. Results indicated that the drug exerts a dose-related effect. Total doses up to 8 micrograms/mouse did not cause any visible damage to Schwann cells. Higher doses induced not only damage to individual cells, but also affected a greater percentage of them. The myelin sheath was the most affected organelle. Schwann cells of myelinated fibers showed greater damage than those of unmyelinated fibers.