방사선 조사로 인한 흰쥐 말초신경 슈반세포의 미세구조 변화

Abstract

To investigate the radiation effects on Schwann cells in the peripheral nervous system, we have irradiated 250rads-dosage on the whole body of 2-day-old rats of Sprague-Dawley strains. Two months later, rats of the control and radiation groups were sacrificed and brachial, cervical and tibial nerves were isolated. They were processed for electron mocroscopic examination. The following results are obtained. 1. The nuclei of Schwann cells in the radiation group showed irregular shapes, such as micronucleus and many convolutions. 2. In the cytoplasm, cisternal dilatation of some Golgi apparatus and vacuolization of rER were noted as the radiation changes. 3. The dense bodies, lipofuscin granules and crystalloid bodies were observed in the radiation group, and crystalloid bodies were specific finding in the radiation group. 4. The amount of collagen fibrils were increased in the extracellular space in the radiation group, and their density was also increased. 5. In the radiated group, single Schwann cell-axon units were frequently observed. With the above results, it could be concluded that the irradiation of early postnatal period influenced to the ultrastructure of the Schwann cells of the peripheral nervous system. And these changes in the cytoplasmic organelles of Schwann cells seem to be the major factor myelin synthesis defect.