인체 구강내 섬유아세포의 방사선 감수성에 관한 연구

A study of radiation sensitivity and dose-survival characteristics of human oral fibroblasts

The effects of ionizing radiation on oral mucosal fibroblast were studied in a cultured medium. Radiation at a single dose(1000cGy, 1200cGy, 1400cGy, 1600cGy, 1800cGy and 200cGy0 was delivered to cultured fibroblasts at a dose rate of 50cGy/min in X-ray Linear Accelerator. 2days, 4days and 7days later, the viable cell count and morphologic findings, MTT(3-4-5-Dimethylthiazoy 1-2, 5-diphenyltetrazolium bromide) assays and DNA analysis on mucosal fibroblast were examined to estimate the cytotoxicities and cell recovering activites. The results were: 1. As the amount radiation dose was increased, the cytotoxic effects also increased in all measurements of viable cell count, MTT assay and DNA analysis. 2. Time-dependent changes in the average lethal dose(MTT50) decreased up to 4days, but recovered at 7days. 3. The lethal dose measured via MTT assay was 1346cGy at 4days after radiation, 1960cGy at 7days. The lethal dose 4 and 7 days radiation was higher than that of 2days after radiation. 4. The greatest difference(16%) between cell survival rates 2days after irradiation was between dosages of 1200cGy and 1400cGy in respect to 4days (6%) and 7days(4%). 5. The DNA contents in each groups were generally decreased as the dose of radiation increased. 6. In morphologic studies with inverted photomicrograph, the degenerative changes of the nucleus and nucleoil were increased as the amount of radiation increased, but recovered and regenerated original morpholgoy at 7days.