[Effects of polychlorinated biphenyls on regeneration of the peripheral nerve in rats]

The effects of polychlorinated biphenyls (PCB) on regeneration of the peripheral nerves were investigated in rats. The sciatic nerves were crushed at the mid-thigh level on the last day of 32 days of oral administration of PCB. The sciatic nerves were biopsied from the crushed regions at 1, 2, 4, 8 and 12 weeks after crushing. Myelin thickness on the axon diameter was smaller in the PCB administered group than in the control group. There was no difference between the experimental group and the control group in the density of regenerating fibers and distribution of fiber diameters in unmyelinated fibers. After 12 weeks the number of large diameter myelinated fiber densities was lower in the experimental group than in the control group. These results indicate that PCB may affect the remyelination of the regenerating nerve.