ANTI-INFLAMMATORY EFFECTS OF LOW-INTENSITY MILLIMETER WAVE RADIATION

Abstract

Using the model of zymosan-induced footpad edema in NMRI mice, the mechanisms of anti-inflammatory effects of low-intensity millimeter waves (MW) were studied in comparison with effects of well-known anti- inflammatory drug sodium diclofenac and antihistamine clemastine. A non- specific inflammatory response was induced by injection of 25 µl of zymosan suspension (5 mg/ml) into the left hind paw. Diclofenac (2-20 mg/kg) or clemastine (0.02-0.6 mg/kg) were i.p. administered in 30 min after zymosan injection. In 1 h after zymosan injection, the mice were whole-body exposed to MW (42.0 GHz, 0.1 mW/cm 2 , 20 min) in the far-field zone of pyramidal horn antenna. Specific absorption rate on the surface of mouse skin was about 1.5 mW/g. Animals of the control group were subjected to injection of physiological saline and/or sham-exposed. The footpad edema (relative increase in the paw thickness) and local hyperthermia were measured before and starting from 3 h after zymosan injection up to 8 h. Diclofenac caused a dose-dependent anti-inflammatory effect. Doses of 5-20 mg/kg reduced the footpad edema on increasing in a dose of diclofenac, and at a dose of 20 mg/kg decreased by 60% in comparison with the control. The MW exposure reduced both the footpad edema and hyperthermia by about 20% that was comparable with the effect of single therapeutic dose of diclofenac (3-5 mg/kg). Combined action of ______ * To whom correspondence should be addressed. Andrew B. Gapeyev, Institute of Cell Biophysics of