Synthetic activity of rat blood lymphocytes under acute and continuous gamma-irradiation - fluorescent microspectral study

The effects of different doses of acute and continuous gamma-irradiation on the synthetic activity of rat blood lymphocytes stained with acridine oran ge were studied by fluorescent microspectrometry. Male rats were exposed to acute gamma-irradiation with doses of 7.5, 4 and 3 Gy, or to continuous ir radiation with dose rates of 14.4, 2.1, 1.1 and 0.43 cGy/day, respectively. The changes of the synthetic activity of blood lymphocytes occurred in thr ee main stages after acute gamma-irradiation and in four stages under conti nuous irradiation. The stages reflect the processes of depression and activ ation of the immune system under irradiation. Essential differences between the acute and continuous effects were observed in the first stage. After a cute gamma-irradiation, the synthetic activity decreased sharply, indicatin g the predominant contribution of the damaging effect of irradiation, where as under continuous irradiation, as a result of the stimulatory effect of l ow-dose irradiation, the synthetic activity increased during the first stag e.