Hypoalgesic effect of millimeter waves in mice: Dependence on the site of exposure (original) (raw)
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Pain relief caused by millimeter waves in mice: results of cold water tail flick tests
International Journal of Radiation Biology, 2000
study, naloxone exhibited its inhibitory activity in Purpose : To nd out if millimeter waves can decrease experimental a dose-dependent manner and stereoselectively pain response in mice using cold water tail ick test. (Õ)-naloxone exerted the eÚ ect, while the biologic-Materials and methods: Male Swiss albino mice (15 mice per group) ally inactive enantiomer (+)-naloxone did not. were exposed to continuous millimeter waves at a frequency of Any new method of pain relief is clinically import-61.22 GHz with incident power densities (IPD) ranging from 0.15 to 5.0 mW/cm 2 for 15 min or sham exposed. Latency of ant, especially a non-pharmacological non-invasive tail withdrawal in a cold water (1 Ô 0.5ß C) tail ick test was procedure such as mm waves. To verify some of the measured before the exposure (baseline) and then four times clinical reports, published mostly in the Russian after the exposure with 15 min breaks. language (Lyan and Votoropin 1996, Shliapak et al. Results: The mean latency of the tail ick response in mice 1996, Vinogradov et al. 1993), Lyan and Votoropin exposed to millimeter waves was more than twice that of shamexposed controls (p< 0.05). This eÚ ect was proportional to the 1996, Shliapak et al. 1996, Bakalyuk 1997), a doublepower of millimeter waves and completely disappeared at an blind phase I pilot clinical trial was conducted with IPD level of < 0.5 mW/cm 2. Pretreatment of mice with the healthy human volunteers, and it was found that mm opioid antagonist naloxone (1 mg/kg i.p.) blocked the eÚ ect of waves suppressed experimental pain (cold pressor millimeter waves. test) in human subjects (Radzievsky et al. 1999). Conclusions : Results suggest that the antinociceptive eÚ ect of millimeter waves is mediated through endogenous opioids.
The involvement of cutaneous receptors in the biological effects of electromagnetic millimeter waves
Archives of Biological Sciences, 2014
The involvement of peripheral nerve terminations in the mechanisms of action of electromagnetic millimeter waves (mmW) was assessed. It is currently thought that mmW could be used in noninvasive complementary therapy because of their analgesic effect. However, the mechanisms of their antinociceptive effect and non-ionizing radiation are the subjects of controversy. The mechanisms of interaction of mmW and the cutaneous tissue have not been elucidated. We observed mast cell degranulation at the place of mmW action, a decrease of chronaxie and Turck reflex time, an increase in the number of afferent impulses after sciatic nerve at stimulation, as well as an increase electrocardiogram R-R interval of isolated frog heart after application of mmW. Based on these investigations, we propose that electromagnetic waves of millimeter length modify, through indirect mechanisms, the excitability and reactivity of peripheral nerve terminations.
Antipruritic effect of millimeter waves in mice: Evidence for opioid involvement
Life Sciences, 1998
In our previous studies, exposure of mice to millimeter waves (MW) increased the duration of anesthesia caused by either ketamine or chloral hydrate, and this effect was blocked by naloxone. To further characterize the biological effects of MW, we have chosen a new animal model of experimental itch. Male Swiss albino mice were injected S.C. in the rostral part of the back with the pruritogenic agent, compound 48/80, with or without naloxone pretreatment. After a 15-min exposure of mice to MW (frequency, 61.22 GHz; incident power density, 15 mW/cm'), the number of scratches of the injected site was counted for 90 min post-injection. MW inhibited the scratching activity of mice by more than 2 times in comparison with the sham-exposed controls (pcO.005). Pretreatment of animals with (-)-naloxone (0.1-1.0 m@g, i.p.) suppressed the antipruritic effect of MW in a dose-dependent manner, while the inactive enantiomer (+)-naloxone at 1 mg/kg did not alter the effect. These results suggest that MW trigger the release of opioids in exposed subjects. 0 1998 Elsevier Science Inc.
Millimeter wave effects on electrical responses of the sural nerve in vivo
Bioelectromagnetics, 2009
Millimeter wave (MMW, 42.25 GHz)-induced changes in electrical activity of the murine sural nerve were studied in vivo using external electrode recordings. MMW were applied to the receptive field of the sural nerve in the hind paw. We found two types of responses of the sural nerve to MMW exposure. First, MMW exposure at the incident power density ≥45 mW/cm2 inhibited the spontaneous electrical activity. Exposure with lower intensities (10–30 mW/cm2) produced no detectable changes in the firing rate. Second, the nerve responded to the cessation of MMW exposure with a transient increase in the firing rate. The effect lasted 20–40 s. The threshold intensity for this effect was 160 mW/cm2. Radiant heat exposure reproduced only the inhibitory effect of MMW but not the transient excitatory response. Depletion of mast cells by compound 48/80 eliminated the transient response of the nerve. It was suggested that the cold sensitive fibers were responsible for the inhibitory effect of MMW and radiant heat exposures. However, the receptors and mechanisms involved in inducing the transient response to MMW exposure are not clear. The hypothesis of mast cell involvement was discussed. Bioelectromagnetics 31:180–190, 2010. © 2009 Wiley-Liss, Inc.
Bioelectromagnetics, 2008
Millimeter wave treatment (MMWT) is based on the systemic biological effects that develop following local skin exposure to low power electromagnetic waves in the millimeter range. In the present set of experiments, the hypoalgesic effect of this treatment was analyzed in mice. The murine nose area was exposed to MMW of “therapeutic” frequencies: 42.25, 53.57, and 61.22 GHz. MMWT-induced hypoalgesia was shown to be frequency dependent in two experimental models: (1) the cold water tail-flick test (chronic non-neuropathic pain), and (2) the wire surface test (chronic neuropathic pain following unilateral constriction injury to the sciatic nerve). Maximum hypoalgesic effect was obtained when the frequency was 61.22 GHz. Other exposure parameters were: incident power density = 13.3 mW/cm2, duration of each exposure = 15 min. Involvement of δ and κ endogenous opioids in the MMWT-induced hypoalgesia was demonstrated using selective blockers of δ- and κ-opioid receptors and the direct ELISA measurement of endogenous opioids in CNS tissue. Possible mechanisms of the effect and the perspectives of the clinical application of MMWT are discussed. Bioelectromagnetics 29:284–295, 2008. © 2007 Wiley-Liss, Inc.
Electromagnetic MW Induced Hypoalgesia: Frequency Dependence and Involvement of Endogenous Opioids
Millimeter wave treatment (MMWT) is based on the systemic biological effects that develop following local skin exposure to low power electromagnetic waves in the millimeter range. In the present set of experiments, the hypoalgesic effect of this treatment was analyzed in mice. The murine nose area was exposed to MMW of ''therapeutic '' frequencies: 42.25, 53.57, and 61.22 GHz. MMWTinduced hypoalgesia was shown to be frequency dependent in two experimental models: (1) the cold water tail-flick test (chronic non-neuropathic pain), and (2) the wire surface test (chronic neuropathic pain following unilateral constriction injury to the sciatic nerve). Maximum hypoalgesic effect was obtained when the frequency was 61.22 GHz. Other exposure parameters were: incident power density ¼ 13.3 mW/cm 2 , duration of each exposure ¼ 15 min. Involvement of d and k endogenous opioids in the MMWT-induced hypoalgesia was demonstrated using selective blockers of dand k-opioid receptors and the direct ELISA measurement of endogenous opioids in CNS tissue. Possible mechanisms of the effect and the perspectives of the clinical application of MMWT are discussed.
Role of field intensity in the biological effectiveness of millimeter waves at a resonance frequency
Bioelectrochemistry and Bioenergetics, 1997
The study replicated the effect of low-intensity millimeter waves (MMW) on isolated nerve function and characterized its dependence on radiation intensity. Mh4W exposures lasted for 23 min at 0.02, 0.1, 0.5, or 2.6 mW cm -* (41.34 GHz) and were accompanied by a high-rate electrical stimulation of the nerve (I-IRS, 20 twin pulses s-', 9 ms inter-pulse interval). MMW had no effect on the conditioning compound action potentials (CAPS), but significantly attenuated the HRS-caused decrease of the test CAPS. The magnitude of this effect was virtually the same (20-25%) at field intensities of 0.02, 0.1, and 2.6 mW cme2. Irradiation at 0.5 mW cm-*, however, did not produce statistically significant changes. The results are consistent with our earlier observations of this MMW effect and provide further evidence for its nonthermal mechanism. 0 1997 Elsevier Science S.A.
Single millimeter wave treatment does not impair gastrointestinal transit in mice
Life Sciences, 2002
Millimeter wave treatment (MWT) is based on those biological effects that develop following skin exposure to low power electromagnetic waves. This method of treatment is in wide clinical use in several Eastern European countries for treatment of a variety of conditions, including pain syndromes. However, most treatment modes of MWT were developed empirically, and certain indications and contraindications for the use of MWT remain to be established. In our previous blind experiments we have shown that the hypoalgesic effect of MWT may be quantitatively evaluated, and most probably mediated by the neural system in general, and the system of endogenous opioids in particular. Taking in consideration a well-known ability of opioids to cause gastrointestinal disturbances, which could limit clinical application of MWT, the main aim of the present study was to investigate whether a single MWT, that can produce opioid-related hypoalgesia, may also retard gut transit and colorectal passage in mice. The charcoal meal test was used to quantitatively evaluate upper gastrointestinal transit, and the glass bead test was employed to examine colonic propulsion in mice. MWT was applied to the nose area of mice. The MWT characteristics were: frequency = 61.22 GHz; incident power density = 15 mW/cm 2 ; and duration = 15 min. The results obtained have shown that MWT does not significantly change small intestinal or colonic transit in mice, and thus suppression of gastrointestinal motility should not be a setback in the clinical use of MWT. D
Search for frequency-specific effects of millimeter-wave radiation on isolated nerve function
Bioelectromagnetics, 1997
Effects of a short-term exposure to millimeter waves (CW,(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52).0 mW/cm 2 ) on the compound action potential (CAP) conduction were studied in an isolated frog sciatic nerve preparation. CAPs were evoked by either a low-rate or a high-rate electrical stimulation of the nerve (4 and 20 paired pulses/s, respectively). The low-rate stimulation did not alter the functional state of the nerve, and the amplitude, latency, and peak latency of CAPs could stay virtually stable for hours. Microwave irradiation for 10 -60 min at 0.24 -1.5 mW/cm 2 , either at various constant frequencies or with a stepwise frequency change (0.1 or 0.01 GHz/min), did not cause any detectable changes in CAP conduction or nerve refractoriness. The effect observed under irradiation at a higher field intensity of 2 -3 mW/cm 2 was a subtle and transient reduction of CAP latency and peak latency along with a rise of the test CAP amplitude. These changes could be evoked by any tested frequency of the radiation; they reversed shortly after cessation of exposure and were both qualitatively and quantitatively similar to the effect of conventional heating of 0.3 -0.4 ЊC. The high-rate electrical stimulation caused gradual and reversible decrease of the amplitude of conditioning and test CAPs and increased their latencies and peak latencies. These changes were essentially the same with and without irradiation (2.0 -2.7 or 0.24 -0.28 mW/cm 2 ), except for attenuation of the decrease of the test CAP amplitude. This effect was observed at both field intensities, but was statistically significant only for certain frequencies of the radiation. Within the studied limits, this effect appeared to be dependent on the frequency rather than on the intensity of the radiation, but this observation requires additional experimental confirmation.
Low-Intensity Electromagnetic Millimeter Waves for Pain Therapy
Evidence-Based Complementary and Alternative Medicine, 2006
Millimeter wave therapy (MWT), a non-invasive complementary therapeutic technique is claimed to possess analgesic properties. We reviewed the clinical studies describing the pain-relief effect of MWT. Medline-based search according to review criteria and evaluation of methodological quality of the retrieved studies was performed. Of 13 studies, 9 of them were randomized controlled trials (RCTs), only three studies yielded more than 3 points on the Oxford scale of methodological quality of RCTs. MWT was reported to be effective in the treatment of headache, arthritic, neuropathic and acute postoperative pain. The rapid onset of pain relief during MWT lasting hours to days after, remote to the site of exposure (acupuncture points), was the most characteristic feature in MWT application for pain relief. The most commonly used parameters of MWT were the MW frequencies between 30 and 70 GHz and power density up to 10 mW cm−2. The promising results from pilot case series studies and small...