[Effects of polychlorinated biphenyls on regenerating myelin of peripheral nerve in rats]

The effects of polychlorinated biphenyls (PCB) on regenerating myelin of the peripheral nerves were investigated in rats. The sciatic nerves were crushed at the mid-thigh level on the last of 32 days of oral administration of PCB. The sciatic nerves were biopsied from the crushed regions at 4, 8 and 12 weeks after crushing. The nerves were fixed in 2.5% glutaraldehyde buffered with 0.1 M sodium cacodylate and embedded in epon 812. The ultrathin sections were analysed by JEOL JEM-1210 with EDAXDX-4. The chloride which was composed of PCB was increased in myeline on 4 weeks after crushing. Freeze fracture study of myelines of sciatic nerves on 8 and 12 weeks after crushing showed an increase of intramembranous particle on 12 weeks and an increase of caveolae on 8 weeks. These results suggest that PCB may affect the plasmamembrane of shwann cell and induce the disturbance of myeline.