Effects of Ionizing and Nonionizing Radiation on rat Hemopoiesis

Abstract

Alterations of the marrow cellularity in male Wistar rats under the combined action of millimeter waves (MMW) and gamma rays were studied. MMW with wavelength of 5.6 mm (frequency 53.53 GHz) or 7.1 mm (42.19 GHz) were applied to the right hindleg shank of the animal for 20 min daily for 10 days using a Yav'-1 generator (Russia). Two of the test groups were also irradiated with gamma rays (6 Gy) immediately following the last treatment with MMW. Nucleus-containing cells in the marrow from a 1-cm-long piece of thigh bone were counted on days 3, 7, 14, 21, and 30 after the last treatment with MMW or after the gamma irradiation. The treatment of the animals with 5.6 mm electromagnetic waves (EMW) only showed an increase of marrow cellularity compared to the control group after day 14 until the end of the investigation period. An increase in marrow cellularity after exposure to 7.1 mm EMW was observed at the seventh day following exposure. Exposure of the rats to MMW prior to gamma irradiation reduced the radiation damage of hemopoiesis in the early postirradiation period. The exposure to MMW increased the quantity of marrow karyocytes after the ionizing exposure and preserved the proliferating capability of the stem cells and their active differentiation. The results of this study showed that bone marrow cellularity returned to control values on day 7 after gamma irradiation, and greater effect was achieved using 7.1 mm EMW.