In a previous study (Meng et al. 2007) it was shown that low-dose microwave exposure increased the survival rate of mice irradiated with 8-Gy gamma rays. However, the underlying mechanisms remained unknown.
96 mice were divided into four groups: 1) control group, 2) microwave exposure group, 3) gamma rays (5 Gy) exposure group, and 4) co-exposure group (microwave + gamma rays). Mice were sacrificed 3, 6, 9, or 12 days (six mice each day of each group) after the gamma ray exposure.
Exposure duration: continuous for 1 h/day on 14 days
The data showed that pre-exposure to low-dose microwaves attenuated hematopoietic injuries produced by subsequent gamma radiation. The protective effects of microwave exposure appeared to be related to 1) up-regulation of some hematopoietic growth factors, 2) stimulation of proliferation of the granulocyte-macrophages in bone marrow, and 3) antagonism of the gamma ray-induced inhibition of hematopoietic stem cells/hematopoietic progenitor cells.