不同参数电针对内源性阿片肽系统调节的量效关系

Endogenous opioid peptides(EOP)are the neurochemical basis of the anesthetic and analgesic effects of acupuncture,and the quantity of acupuncture stimulus can be controlled accurately by using electroacupuncture(EA).The present study explores the dose-effect relationship between EA with different parameters and the regulation of EOP system.In this paper,the intervention effects of EA on EOP system were specially discussed in terms of the single factor and the different combinations of the frequency,waveform and current intensity.This study shows that EOP system presents a frequency-response specificity.The low frequency of EA promotes the release of enkephalin,β-endorphin and endomorphin,the high one activates the dynorphin system selectively,and the intermediate frequency works on promoting the release of enkephalin andβ-endorphin,as well as dynorphin.Sparse-dense wave of EA may induce the release of enkephalin,β-endorphin,endomorphin and dynorphin,presenting a synergistic effect.However,the waveform of EA should be selected flexibly in clinical practice.Sometimes the better therapeutic effect can also be obtained with the continuous wave of EA.EOP system is involved in mediating appropriate intensity of EA,while the acupuncture effect generated by an extra strong EA stimulation refers to a kind of stress response of non-opioid mechanism.The different combinations of EA parameters result in various effects.The combination of EA parameters should be optimized in accordance with different diseases,which is valuable for guiding clinical practice and the development of EA therapy.

电针镇痛及其与刺激参数的量效关系研究:近三十年研究新进展

In this review,we explored the dose-effect relationship of electroacupuncture(EA)analgesia and its stimulus parameters by searching articles on clinical and experimental research of EA analgesia in the past30 years.The impacts on the analgesic effects are discussed in terms of the pulse waveform,frequency,amplitude,wave width,and time effect,as well as parameter combinations,and the optimization of the EA parameters are summarized for the treatment of neuropathic,inflammatory,and cancer pains.It was initially discovered that the distant-dense(D-D)wave(2/15 Hz or 2/100 Hz)and stimulus for 30-45 min were appropriate in the treatment of chronic inflammatory pain,the strong stimulus was applicable to the acute stage of pain(twice a week),while the weak stimulus was for the stable stage(once weekly).The continuous(2 Hz)/D-D wave(2/100 Hz)and moderate/low intensity of stimulus for 30-45 min are preferred in the treatment of neuropathic pain with EA,once daily or every 2 days.Regarding the treatment of cancer pain,EA with continuous(2 Hz or 100 Hz)or D-D wave(2/100 Hz),moderate and low intensity of stimulus for 30-45 min is adopted,once every 2 days.There is a certain rule for the correlation of each parameter and the combination of parameters to ensure an analgesic effect of EA,which should be further explored in future studies.

Medulla Oblongata Mechanism of Inhibitory Effect of Thermal Stimulation to Nociceptive Colorectal Distention in Rats

Objective: To discuss mechanism of moxibustion(thermal stimulation) effect and best moxibustion stimulus parameter.Methods: Experiments were performed on 48 male Sprague-Dawley rats. Unit discharges from individual single neuron were recorded extracellularly with glass-microelectrode in Subnucleus Reticularis Dorsalis(SRD). Visceral-intrusive stimulation is done by colorectal distension. Thermal stimulation with different temperature(40°C, 42°C, 44°C, 46°C, 48°C, 50°C, 52°C) and different stimulus area(diameter of circle : 1.0 cm, 1.5 cm, 2.0 cm, 2.5 cm, 3.0 cm, 3.5 cm, 4.0 cm) was applied around RN12 during nociceptive colorectal distension.Results: SRD neurons could be activated by visceral stimulation within noxious range. Under low temperature of stimulus, especially under45°C of pain threshold to ordinary people, visceral nociceptive afferent facilitated thermal stimulus from the body surface. While after thermal stimulation reached a harmful degree, the thermal stimulus will inhibit visceral nociceptive afferent. Moreover, statistics show that the higher the temperature is, the smaller the size of stimulation area is needed, and they correlate with each other negatively.Conclusion: Visceral nociception could be inhibited by somatic thermal stimulation with specific parameter at medulla level. According to our finding, best thermal stimulation temperature is around 48°C and the best size of stimulation area is around 3.14-7.07 cm2(with 2.0-3.0 cm diameter).