Regeneration of unmyelinated peripheral axons in vitamin E-deficient rats.

Unmyelinated axons of normal and regenerated sciatic nerve were counted in controls and vitamin E-deficient rats. No significant change in the number of unmyelinated axons of uninjured nerve was found in the vitamin E deficiency in comparison to controls (12961 +/- 1591 and 12450 +/- 1290, respectively, mean +/- SEM). In regenerated nerve of control rats the number of unmyelinated axons was higher than in uninjured nerve (16971 +/- 1854 and 20786 +/- 1574 at 1 and 2 months after crush, respectively). In vitamin E-deficient rats the increase in number of unmyelinated axons was greater than in corresponding controls (21880 +/- 662) at 1 month after lesion, but the number returned to value found in uninjured nerve at 2 months after lesion (12536 +/- 659). These results suggest that sprouting at lesion may be enhanced but some regenerated axons does not survive at long term in vitamin E-deficiency.