Recovery from X-ray Induced Damage in Primary Cultures of Human Skin Fibroblast Cells

Abstract

Human skin fibroblast cells from six patients were obtained during surgical operations and grown in culture. Dose response survival curves from single dose exposures of X-rays were developed for the six cell strains. Individual D₀ values varied in the six strains from 61 to 83 cGy. The shouldered survival curves had extrapolation numbers (n) ranging from 2.2 to 4.8. To assess repair of sublethal damage, cells were exposed to a total dose of 304 cGy split into two equal fractions separated by varying time intervals. Maximal increase in cell survival was observed when the time interval was at least three hours. Dose-response curves were generated for the six cell strains by first irradiating cells with 152 cGy X-rays and then allowing four hours for recovery from sublethal damage before exposing them to second graded doses. The fractionated dose-response survival curves were distinctly different from the single dose exposure curves and confirmed the ability of these cells to recover from X-ray-induced damage.