Electroacupuncture attenuates inflammation in a rat model
ABSTRACT Acupuncture has traditionally been used in China and is being increasingly applied in Western countries to treat a variety of conditions, including inflammatory disease. However, clinical trials investigating the effectiveness of the anti-inflammatory effects of acupuncture have yielded inconsistent results, and the underlying mechanisms of acupuncture-produced anti-inflammation are unclear.
To evaluate the effectiveness of electroacupuncture (EA) on inflammation in a rat model.
Four experiments were conducted on male Sprague-Dawley rats (n = 8-9 per group). Inflammation was induced by injecting complete Freund's adjuvant (CFA) subcutaneously into the plantar surface of one hind paw of the rat. Experiment 1: To determine the effect of EA (10 and 100 Hz) versus sham treatment on inflammation. Experiment 2: To investigate the involvement of the adrenal glands on the effect of EA treatment using adrenalectomized (ADX) rats. Experiment 3: To determine the effects of EA on plasma levels of corticosterone. Experiment 4: To determine the effects of EA treatment versus immobilization on such stress indicators as heart rate and blood pressure.
At 10 Hz EA significantly reduced CFA-induced hind paw edema. The effect was partially blocked in the ADX rats. EA significantly increased plasma levels of corticosterone but produced no noticeable signs of stress.
At 10 Hz but not 100 Hz, EA suppresses inflammation by activating the hypothalamus-pituitary-adrenal axis (HPA) and the nervous system.
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ABSTRACT: The mechanism of acupuncture analgesia (AA) has been widely explored since the 1970s. Early studies investigated the relationship between acupuncture and endogenous opiates (beta-endorphin, enkephalin, endomorphin and dynorphin). Before the 1990s, most experts agreed on the concept that in normal animal models, lower frequency electroacupuncture (EA) stimulates the release of beta-endorphin, enkephalin and endomorphin, which in turn activates the mu- and delta-opioid receptors, and that higher frequency EA stimulates dynorphin which activates the kappa-opioid receptor. Besides endogenous opiates, our studies have focused on serotonin. The serotoninergic descending inhibitory pathway is suggested to be an important mechanism of acupuncture analgesic, collaborating with endogenous opiates. Many efforts have been made to clarify these mechanisms, but to date no satisfactory consensus has been reached. In the late 1990s, researchers began to focus on the different analgesic effects of EA between normal and hyperalgesic animal models. Published data from these studies imply that normal and hyperalgesic animals respond differently to EA. Results from experiments on the anti-hyperalgesia effect of EA have raised a new issue about the influences of EA on receptors to excitatory amino acid in the spinal cord level. Results from various studies have shown that these receptors play a role in the mechanism of AA. Recently, research on the autonomic nervous system (ANS) seem to indicate its connection with acupuncture. The inflammatory reflex (via the ANS) might be a crucial part of anti-hyperalgesia elicited by acupuncture, and this reflex, which regulates the immune system in the organism, can elucidate not only the mechanism of AA but also the mechanism of acupuncture applied to other inflammatory conditions. Innovation of functional image study enables us to analyze the responses of cortex on living human body to acupuncture. However, results of these experiments are still controversial. After 30 years of acupuncture research, there are still many puzzles left to be solved regarding the mechanism of AA.The American Journal of Chinese Medicine 02/2008; 36(4):635-45. DOI:10.1142/S0192415X08006107 · 2.63 Impact Factor
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ABSTRACT: To investigate the efficacy of acupuncture in the treatment of moderate obstructive sleep apnea syndrome (OSAS), assessed by polysomnography (PSG) and questionnaires of functional quality of life (SF-36) and excessive daytime sleepiness (Epworth). We performed a randomised, placebo-controlled, single-blinded study, with blinded evaluation on 36 patients presenting an apnea/hypopnea index (AHI) of 15-30/h, assessed by PSG. The study took place at the Public Hospital of the Universidade Federal de São Paulo, Brazil, in the Division of Sleep Disorders of the Department of Psychobiology, between January, 2002 and August, 2004. Patients were randomly assigned to three groups: the acupuncture group (n=12); the sham group, submitted to needle insertion in non-acupoints (n=12); and the control group, receiving no treatment (n=12). Patients received acupuncture or sham acupuncture once a week for 10 weeks. Twenty-six patients completed the study. The AHI (P=0.005), the apnea index (AI) (P=0.008) and the number of respiratory events (P=0.005) decreased significantly in the acupuncture group but not in the sham group. On the other hand, the control group displayed significant deterioration in some of the polysomnographic parameters, with a significant increase in the number of respiratory events (P=0.025). Acupuncture treatment significantly improved (before vs. after treatment) several dimensions of the SF-36 and Epworth questionnaires. There was no significant association between changes in the body mass index (BMI) and AHI. Acupuncture is more effective than sham acupuncture in ameliorating the respiratory events of patients presenting with moderate OSAS.Sleep Medicine 02/2007; 8(1):43-50. DOI:10.1016/j.sleep.2006.04.009 · 3.10 Impact Factor
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ABSTRACT: Our previous study showed that electroacupuncture (EA), an adjuvant to conventional medicine, significantly attenuated hyperalgesia in a rat model of inflammatory pain. In the present study, we evaluated the potential additive and/or synergism of EA and a sub-effective dose of dizocilpine maleate (MK-801), a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, on hyperalgesia in the same rat model of inflammatory pain. Hyperalgesia, manifesting as decreased paw withdrawal latency (PWL) to a noxious stimulus, was induced by injecting complete Freund's adjuvant (CFA) into the plantar surface of one hind paw of each rat. EA treatments were given at acupoint GB30 immediately after and 2 h after CFA. MK-801 at 0.001 mg/rat was given (i.t.) 10 min before each of the two EA treatments. PWL was measured prior to and 2.5 and 5 h post-CFA. Ten and 100 Hz EA significantly inhibited CFA-induced hind paw hyperalgesia. Both 10 and 100 Hz EA combined with the sub-effective dose of 0.001 mg/rat MK-801 showed prolonged anti-hyperalgesia with no side effects. These results demonstrate that EA combined with a sub-effective dose of this NMDA receptor antagonist enhances anti-hyperalgesia, and this combination may provide an effective strategy for pain management.Pharmacology Biochemistry and Behavior 06/2005; 81(1):146-51. DOI:10.1016/j.pbb.2005.03.002 · 2.82 Impact Factor