Pathophysiological responses of MRC-5 cells exposed to various doses of x-ray radiation

The numbers of x-ray procedures used as diagnostic tools are on the rise; these procedures are being used more frequently than ever before. The radiation effect from these procedures are said to be minimal, however there is a significant increase in cellular damage that may lead to cellular aberrations. The objective of this study was to expose human lung fibroblast (MRC-5) cells to various doses of x-ray radiation and evaluate its effects on the proliferation and morphology of the cells. Based on the review of the literature, we selected doses similar to other researchers, the doses were 2, 6 and 10 (Gy), evaluated after 24, 48 and 72 hours of incubation. The results indicated a 25% decrease in the cell number after 48 and 72 hours (p < 0.05), in all groups exposed to either dose of radiation. After 24 hours, there was not a statistically significant difference between the groups exposed to either dose of radiation. Morphologically, the cells exhibited significant changes when exposed to either, 2, 6 or 10 Gy of radiation. The cells showed multiple nucleoli with all doses, and mitotic figures were observed with a dose of 2 Gy. After a dose of 6 Gy, hydropic swelling due to excess fluid in the cytoplasm was noted as well as multiple nucleoli. After 48 and 72 hours, severe vacuolization with various degrees of hypertrophy and atrophy was noted with a dose of 10 Gy. Further analysis revealed that the higher the radiation dose, the more severe the damage after 48 and 72 hours, however, significant damage was evident with all doses, even as low as 2 Gy.