INFLUENCE OF LOW-DOSES OF GAMMA-IRRADIATION ON MOUSE SKIN COLLAGEN FIBRILS

The structure of mouse skin collagen fibrils after treatment with 0.5, 1 and 2.5 Gy gamma-irradiation was studied by electron microscopy. An imals were sacrificed 1, 4 and 8 weeks after irradiation. Although the re were areas where the normal parallel packing of fibrils was retaine d in some regions packing was interrupted by abnormal fibrils and in s ome cases helical twisting was apparent. Irradiated collagen fibrils h ad a lower mean diameter compared with normal and a large variability in width. The diameter of 0.5 Gp irradiated fibrils returned to normal by 4 or 8 weeks after irradiation. Clusters of abnormal fibrils were found when viewed in cross-sections. Their number and size was reversi bly dependent on the dose level. All fibrils retained normal banding p eriodicity. Computer analysis of irradiated and control patterns led t o the conclusion that 0.5-2.5 Gy gamma-irradiation had no considerable effect in modifying the charge distribution along the mouse skin coll agen fibril.