OBJECTIVETo study the development of changes for Raf kinase inhibitor protein (RKIP) and its mRNA in rats hippocampus after electromagnetic radiation.

METHODSRats were exposed to X-band high power microwave (X-HPM), S-band high power microwave (S-HPM) and electromagnetic pulse (EMP) radiation source respectively. The animal model of electromagnetic radiation was established. Western blot was used to detect the expression of RKIP, and RT-PCR was applied to detect the expression of RKIP mRNA. The interaction of RKIP and Raf-1 was measured with co-immunoprecipitation method, and the expression of cerebral choline acetyltransferase (CHAT) was measured by immunohistochemistry.

RESULTSThe expression of RKIP significantly down-regulated at 6 h after radiation, and recovered at 1 d in group EMP, but the down-regulation continued during 1 approximately 7 d after radiation in the two microwave groups. The expression of RKIP mRNA changed wavily during 6 h approximately 7 d after radiation, which showed down-regulation at 6 h, and up-regulation at 3 d. The interaction of RKIP and Raf-1 decreased during 6 h approximately 7 d after radiation, most significantly at 7 d, and the two microwave groups were more significant. The expression of CHAT decreased continuously during 6 h approximately 7 d after radiation, and generally recovered on 14 d.

CONCLUSIONThe down-regulation of RKIP and its related proteins of hippocampus is induced by electromagnetic radiation.