Genetic Markers of Host Resistance and/or Susceptibility to the Lethal Effects of Radiation and Combined Radiation-Burn Injuries

摘要

The results suggest that strains of rats of differing genetic backgrounds differ widely in their susceptibility to the lethal effects of ionizing radiation. Just as has been observed in the same species with thermal injury, the capacity of rats to withstand the lethal effects of irradiation appear to be governed by genetic factors. The 8 inbred and 2 randomly bred strains of rats tested could be grouped (on the basis of LD50/30 determinations) into three categories, ranging from highly susceptible (ACI and BN) strains to 5 strains of intermediate susceptibility (W, OM, SD, LEW DA) and to 3 highly resistant, i.e., least susceptible strains (WF, F344, BUF). As observed earlier with thermal injury, females of the same strain were more susceptible to the lethal effects of radiation; this effect was particularly marked in pigmented strains. Two inbred pigmented strains bearing train hi/hi (homozygous recessive Irish gene for coat color) were the most susceptible to radiation vis-a-vis 7 other albino strains and one other pigmented strain (DA), which lacks the hi/hi gene. There may therefore be an association between skin pigmentation and/or coat color and the genetic determinants of susceptibility to the lethal effects of radiation. Comparison of the susceptibility of the same strains to the lethal effects of severe thermal injury provides no evidence of a parallel influence of skin pigmentation or coat color upon such susceptibility. While one pigmented strain (ACI) was most highly susceptible, the other pigmented strain (BN) was in the least susceptible category. The evidence also points to the probability that MHC factors are not involved in conditioning host susceptibility to severe radiation injury.