AN ELECTRON MICROSCOPIC STUDY OF THE IRRADIATION EFFECTS ON THE RAT PAROTID INTERCALATED DUCT CELLS

방사선조사가 타액선 도관세포에 미치는 영향에 관한 전자현미경적 연구

This study was designed to investigate the effects of irradiation on the salivary ductal cells, especially on the intercalated ductal cells of the rat parotid glands. For this study, 36 Sprague-Dawley strain rats were irradiated on the head and neck region with absorbed dose of 15Gy by Co-60 teletherapy unit, Picker's model 4M60. The conditions irradiated were that field size, SSD, dose rate and depth were 12×5㎝m, 50㎝, 222 Gy/min. and 1㎝. respectively. The experimental animals were sacrificed 1, 2, 3, 6, 12 hours and 1, 3, 7 days after the irradiation and the changes of the irradiated intercalated duct cells of the parotid glands were examined under the light and electron microscope. The results were as follows: 1. Under the light and electron microscope, the nucleus, mitochondria and secretory granules showed severe changes in the early stage after irradiation and the most severe cellular de- generations were observed 2 hours after irradiation, but the repair processes began from 6 hours after irradiation. 2. Under the electron microscope, loss of the nuclear membranes, derrangement of the chromosomes, swelling and destruction of the secretory granules, and widening of the intercellular spaces were observed after irradiation. 3. Under the light microscope, atrophy and irregular proliferation of the ductal cells, cuboidal metaplasia, hyperchromatism, and the construction or obstruction of the lumen were observed after irradiation.