[Action of the red and infrared electromagnetic waves of light-emitting diodes on the behavioral manifestation of somatic pain].

Research of analgesic action of electromagnetic waves (EMWs) of red (1 = 640 +/- 30 nm) and infra-red (1 = 880 +/- 30 nm) light-emitting diodes of device "MEDOLIGHT" on a tonic and acute pain of white outbreed male mice is carried out. The tonic pain was caused by hypodermic injection of 20 ml of 5% formalin solution in a back surface pad of a hinder leg. Acupuncture point (AP) E-36 or the center of pain were exposed to the action of red or infrared light-emitting diodes in cumulative density of steam radiation capacity during 10 min by 26 mWt/ cm2 in continuous or pulse regimen for frequencies 10, 600, 8000 Hz. Quantitative intensity of a painful syndrome was estimated by average group duration or quantity of painful (licking of the center of a pain, twitching of a hinder leg) and non-painful (dream, grooming, eating) behaviour manifistation of animals for the certain intervals of observation. Sensitivity of animals to acute pain--"a painful threshold"--was deter- mined in experiences with "an electric floor" on size of the electric voltage caused vocalization. The analgesic action both continuous, and pulse light-emitting diode EMWs, features of their action in relation to the place of the application and modes of influence were shown. Thus, the continuous stimulation of AP E-36 only by red EMW decreased the duration of pain paw licking on 33% and quantities of twitching of animals paw on 37% while the duration of grooming, dream, and consumption of feed raised. Such changes of painful and nonpainful behaviour unequivocally specify reduction of a tonic pain. Combined action of red and infrared EMWs caused diverse changes of painful reactions of animals and increase of extremity hyperemia. Thus at summary action of EMWs on AP E-36 of mice the long increase of painful sensitivity was observed. Exposure of EMWs to the center of a pain reduced the intensity of painful reactions of mice on 30% in average, time of their movings in a cage increased twice and duration of dream increased by 39%. Thus, summary action of red and infrared EMWs on AP E-36 promoted only to improvement of a blood circulation and increase painful sensitivity. In experiments with a tonic pain the summary pulse action on AP E-36 of the red and infrared EMWs with frequencies 10, 600, 8000 Hz reduced twice quantity of paw twitchings of animals with pain. The greatest efficiency in suppression of tonic pain syndrome observed for frequencies of 10 and 8000 Hz. The data received testify that the hypoanalgesic effect of light-emitting diode EMWs depends on area of influence, lengths of wave and the modes of an irradiation chosen in view of intensity and duration of stimulation.