extremely-high frequency electromagnetic radiation
A.B. Gapeyev, T.P. Kulagina, A.V. Aripovsky, N.K. Chemeris
Previously, using a model of acute nonspecific inflammation in mice, it was shown that low-intensity extremely high-frequency electromagnetic radiation (EHF EMR; 42.2 GHz, 0.1 mW/cm2, exposure duration of 20 min) caused a pronounced anti-inflammatory effect, which was manifested as a decrease in the exudative edema and hyperthermia of the inflammation focus. Basing on a pharmacological analysis, we have suggested that the metabolites of fatty acids (FAs) could be involved in the realization of anti-inflammatory effects of EHF EMR. To test this hypothesis, we studied changes in the content of FAs in thymic cells and the blood plasma of mice exposed to EHF EMR in the norm and during inflammation. Peritoneal inflammation in mice was induced by intraperitoneal injection of zymosan. Individual concentrations of FAs in biological samples were determined by a method of gas chromatography. It was found that the single exposure of normal mice to EHF EMR (42.2 GHz, 0.1 mW/cm2, 20 min) caused significant increase in the content of polyunsaturated FAs (dihomo--linolenic, arachidonic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic) and the decrease in the summary content of monounsaturated FAs in thymic cells. On the contrary, quintuple exposure of normal mice to EHF EMR (20 min daily for five consecutive days) led to a decrease in the content of polyunsaturated FAs (linoleic, arachidonic, docosapentaenoic, and docosahexaenoic) and an increase in the content of monounsaturated FAs (palmitoleic and oleic) in thymic cells. Taking into account the fact that the single exposure to EHF EMR induced significant increase in the content of polyunsaturated FAs, which are precursors of many anti-inflammatory mediators, this exposure regimen was chosen for a treatment of mice with the inflammation. The single exposure of mice with zymosan-induced inflammation caused significant increase in the content of polyunsaturated FAs (dihomo--linolenic, arachidonic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic) and the decrease in the summary content of monounsaturated FAs in thymic cells. Changes in the FA composition in the blood plasma were less pronounced and manifested themselves as an increase in the level of saturated FAs during the inflammation. The results obtained are indicative of a capability of EHF EMR to influence significantly a balance between monounsaturated and polyunsaturated FAs in the norm and during inflammation. It is possible that monounsaturated FAs are replaced by polyunsaturated FAs that can enter into the thymic cells from the external media. Taking into account the fact that the metabolites of polyunsaturated FAs are lipid messengers actively involved in inflammatory and immune reactions, we assume that the increase in the content of n-3 and n-6 polyunsaturated FAs in phospholipids of cellular membranes initiated by low-intensity EHF EMR is one of the key elements in the mechanisms of realization of anti-inflammatory effects of the electromagnetic radiation.