[en] 160 mice of the BALB/C strain of both sexes, aged 3 months, were divided into four equal groups of which two were regularly irritated by a combination of an optical signal and electrical stroke. After one month of irritation one nonirritated and one irritated group were whole body irradiated with an acute dose of 6.65 Gy (1.83 Gy/min), the other two groups were sham irradiated. The mice lived until spontaneous death or one year after irradiation, when the rest of the animals were sacrificed. Malignant tumors were recorded. Irradiation shortened the survival time while the irritation had an appeasing, compensatory effect, more marked in the males than in the females. After irradiation the number and assortment of the tumors increased and the latent period was significantly shorter. In the irritated animals the number and assortment of the malignant tumors were reduced and the latent time period tended to be longer. These differences, however, were not statistically significant. In spite of some differences the response of both sexes to irradiation and irritation or their combination was similar. (author)