[An electron microscopic study of axonal dystrophy in the gracile nucleus of vitamin E deficient and normally aging rats].

Light and electron microscopic studies were carried out on the axonal dystrophy (AD) appearing in the gracile nucleus of normally aging and vitamin E (VE) deficient rats aged 18, 33, and 48 weeks. In both of 2 groups, AD was observed in axon terminals (AT) and axons. The accumulations of mitochondria, various types of dense bodies and tubular structures were common to both dystrophic AT and axons of normally aging and VE deficient rats. Synaptic vesicle-like vesicles, however, were scattered in dystrophic AT and neurofilaments in some of dystrophic axons increased. The incidences and mean areas of AD in VE deficient rats increased with aging much more than in normally aging rats. No essential ultrastructural differences of AD were observed in VE deficient and normally aging rats, but, structural changes of AD were more advanced in VE deficient rats. These results suggest that the formation of AD in AT and axons is accelerated by VE deficiency.