[The effect of singly-administered super-erythematous doses of UV-radiation on the general body resistance of hairless mice].

Male and female nude mice of the HRS strain were exposed to single UV-B-irradiation with biologically effective doses of 1.0 and 1.4 kJ/m2 at an intensity of 0.11 and 0.59 W/m2. The general resistance of animals was measured in terms of skin automicroflora and resistance to Staphylococcus aureus alpha-toxin injected intraperitoneally at LD50. The amount of microorganisms of the back and tail skin (shielded during exposure) did not differ from the control level 1 hour or 1, 3, 7, 14, and 21 days after irradiation. One day after exposure to UV-irradiation at a dose of 1.4 kJ/m2, toxin resistance declined. The lethality rate of mice was 33.6% and 17.9% at an intensity of UV-irradiation equal to 0.59 W/m2 and 0.11 W/m2, respectively. No effect was observed 3 days after UV-irradiation at a dose of 1.0 kJ/m2. It is concluded that single UV-irradiation with 7 MEDs can decrease body resistance, the decrease enhancing with intensity increase.