A high nonulcerating dose of X radiation was given to the lower lip of the rat while shielding the rest of the body. The present report deals with the severe but reversible changes suffered by the majority of the basal cells. Quantitative data of changes in relative volumes and other measurements of the cytoplasm, nucleus, intercellular space, mitochondria, and the Golgi zone were obtained by a stereologic technique of point counting and by other techniques of measurement. These were applied to electron micrographs made of specimens obtained at 2, 6, 26, and 50 hr and at 12 days after irradiation. Demonstrable change denoting damage was found at all time periods up to 50 hr. Reductions in the magnitude of some of these changes began at 26 hr and virtually complete recovery was noted at 12 days. It was concluded that (1) the model system used is suited to the quantitative analysis of early effects of high doses of X radiation and (2) the quantitative methods applied allow monitoring of the degree of damage and recovery against time.

This content is only available as a PDF.
You do not currently have access to this content.