ENHANCED PROLIFERATION AND IL-1 PRODUCTION OF MOUSE SPLENOCYTES BY LOW-DOSE WHOLE-BODY X-IRRADIATION

To elucidate the stimulative effect of low-dose whole-body X-irradiati on on the immune system, in vivo, we studied its effects on some immun e functions of mouse splenocytes. Results show that Concanavalin A (Co n A) and phytohemagglutinin (PHA) responses of splenocytes were signif icantly increased by irradiation of 2.5 cGy and 5 cGy, whereas lipopol ysaccharide (LPS) response was significantly depressed by irradiation of 5 cGy. By irradiation of 2.5 cGy, Con A response was significantly accelerated at each concentration of Con A, but the optimum concentrat ion of Con A shifted to a higher value of 4 mu g/ml from 2 mu g/ml in the control group. when blood plasma obtained from 2.5 cGy irradiated mice was added into the medium at 0.005-1%, the Con A response of sple nocytes in another un-irradiated mouse was significantly accelerated o ver that where the plasma added came from the sham-irradiated control mice. Furthermore, 2.5 cGy whole-body irradiation also enhanced the bi ological activity of intracellular Interleukin-1 (IL-1) of LPS-stimula ted splenocytes.