Changes of pulse rate and skin temperature evoked by electroacupuncture stimulation with different frequency on both Zusanli acupoints in humans

Modulating activity of PVN neurons prevents atrial fibrillation induced circulation dysfunction by electroacupuncture at BL15

BACKGROUND

Circulation dysfunction is a major contributing factor to thrombosis in patients with atrial fibrillation (AF) for which effective interventions are lacking. Growing evidence indicates that regulating the paraventricular nucleus (PVN), an autonomic control center, could offer a novel strategy for treating cardiovascular and circulatory diseases. Concurrently, electroacupuncture (EA) at Xinshu (BL15), a form of peripheral nerve stimulation, has shown efficacy in treating several cardiovascular conditions, although its specific mechanism remains unclear. This study aimed to assess the impact of EA at BL15 on circulatory dysfunction in a rat AF model and investigate the pivotal role of PVN neuronal activity.

METHODS

To mimic the onset of AF, male SD rats received tail intravenous injection of ACh-CaCl2 and were then subjected to EA at BL15, sham EA, or EA at Shenshu (BL23). Macro- and micro-circulation function were evaluated using in vivo ultrasound imaging and laser doppler testing, respectively. Vasomotricity was assessed by measuring dimension changes during vascular relaxation and contraction. Vascular endothelial function was measured using myograph, and the activation of the autonomic nerve system was evaluated through nerve activity signals. Additionally, chemogenetic manipulation was used to block PVN neuronal activation to further elucidate the role of PVN activation in the prevention of AF-induced blood circulation dysfunction through EA treatment.

RESULTS

Our data demonstrate that EA at BL15, but not BL23 or sham EA, effectively prevented AF-induced macro- and micro-circulation dysfunction. Furthermore, EA at BL15 restored AF-induced vasomotricity impairment. Additionally, EA treatment prevented abnormal activation of the autonomic nerve system induced by AF, although it did not address vascular endothelial dysfunction. Importantly, excessive activation of PVN neurons negated the protective effects of EA treatment on AF-induced circulation dysfunction in rats.

CONCLUSION

These results indicate that EA treatment at BL15 modulates PVN neuronal activity and provides protection against AF-induced circulatory dysfunction.

Electroacupuncture at Zusanli and at Neiguan characterized point specificity in the brain by metabolomic analysis

Different point stimulations can induce brain activity in specific regions, and however whether these stimulations affect unique neurotransmitter transmission remains unknown. Therefore, we aimed to investigate the effect of point specificity to the brain by resolving the metabolite profiles. Eighteen Sprague–Dawley rats were randomly divided into three groups: (1) the sham group: sham acupuncture at Zusanli (ST36) without electric stimulation; (2) the Zusanli (ST36) group: electroacupuncture (EA) at ST36; and (3) the Neiguan (PC6) group: EA at PC6. Then, the metabolites from rat brain samples were measured by LC–ESI–MS. The results of a partial least squares discriminant analysis revealed the differences among the sham, ST36, and PC6 groups regarding the relative content of metabolites in the cerebral cortex, hippocampus, and hypothalamus. EA at PC6 resulted in downregulation of adenosine, adrenaline, γ-aminobutyric acid, glycine, and glutamate majorly in hippocampus, and then in cerebral cortex. Otherwise, EA at ST6 resulted in upregulation of adrenaline and arginine in hippocampus, and all stimulations showed barely change of identified neurotransmitters in hypothalamus. These differential metabolite and neurotransmitter profiles prove that brain areas can be modulated by point specificity and may provide a maneuver to understand more details of meridian.

Acupuncture in Inflammatory Bowel Disease

Scientific research into the effects and mechanisms of acupuncture for gastrointestinal diseases including inflammatory bowel disease has been rapidly growing in the past several decades. In this review, we discuss the history, theory, and methodology of acupuncture and review potentially beneficial mechanisms of action of acupuncture for managing inflammatory bowel disease. Acupuncture has been shown to decrease disease activity and inflammation via increase of vagal activity in inflammatory bowel disease. Acupuncture has demonstrated beneficial roles in the regulation of gut dysbiosis, intestinal barrier function, visceral hypersensitivity, gut motor dysfunction, depression/anxiety, and pain, all of which are factors that can significantly impact quality of life in patients with inflammatory bowel disease. A number of clinical trials have been performed to investigate the therapeutic effects of acupuncture in ulcerative colitis and Crohn's disease. Although the data from these trials are promising, more studies are needed given the heterogeneous and multifactorial aspects of inflammatory bowel disease. There is also an important need to standardize acupuncture methodology, study designs, and outcome measurements.

Acupuncture and neuroregeneration in ischemic stroke

Acupuncture is potentially beneficial for post-stroke rehabilitation and is considered a promising preventive strategy for stroke. Electroacupuncture pretreatment or treatment after ischemic stroke by using appropriate electroacupuncture parameters generates neuroprotective and neuroregenerative effects that increase cerebral blood flow, regulate oxidative stress, attenuate glutamate excitotoxicity, maintain blood-brain barrier integrity, inhibit apoptosis, increase growth factor production, and induce cerebral ischemic tolerance.

Electroacupuncture at ST36-ST37 and at ear ameliorates hippocampal mossy fiber sprouting in kainic acid-induced epileptic seizure rats

Our previous study showed that mossy fiber sprouting can occur in the hippocampus region in rats 6 wk after kainic acid-induced epileptic seizure, and this mossy fiber sprouting can facilitate epileptogenesis. Transcutaneous auricular vagal nerve stimulation (VNS), which is similar to cervical VNS, can reduce the occurrence of epileptic seizure in intractable epilepsy patients. Greater parasympathetic nerve activity can be caused by 2 Hz electroacupuncture (EA). Therefore, we investigated the effect of 2 Hz EA at ST-36-ST37 and at the ear on mossy fiber sprouting in kainic-treated Sprague-Dawley rats. The results indicated that applying 2 Hz EA at ST36-ST37 and at the ear for 3 d per week over 6 consecutive weeks can ameliorate mossy fiber sprouting in the hippocampus region of rats. These results indicated that applying 2 Hz EA at ST36-ST37 and at the ear might be beneficial for the treatment and prevention of epilepsy in humans.

The 2 Hz and 15 Hz electroacupuncture induced reverse effect on autonomic function in healthy adult using a heart rate variability analysis

The purpose of the present study was to investigate effect of electro-acupuncture (EA) at different frequencies on autonomic function. Twenty healthy adult volunteers were studied, and underwent 4 sessions of EA (sham, 2 Hz, 15 Hz, and 50 Hz). Sham, 2 Hz, 15 Hz, and 50 Hz EA was applied to the bilateral Leg Three Li (足三里 zú sān lǐ, ST-36) and Upper Great Hollow (上巨虛 shàng jù xū, ST-37) acupoints. The intensity of electrical stimulation was adjusted to obtain visible twitching of the anterior tibial muscle about 2.0-2.5 mA except sham without electrical stimulation. The components of heart rate variability (HRV) and blood pressure were measured before EA (BLP), EA (EAP), and post-EA periods (PEP). The results indicated that the natural logarithmic high frequency power (lnHF) of HRV was greater during PEP than during the BLP in the 2 Hz EA sessions. The natural logarithmic low frequency power (lnLF) of HRV was greater during the PEP than during the BLP in 15 Hz EA sessions, suggesting that 2 Hz EA apply to Leg Three Li (足三里 zú sān lǐ, ST-36) and Upper Great Hollow (上巨虛 shàng jù xū, ST-37) acupoints increased vagal activity, whereas 15 Hz EA increased sympathetic activity.

The possible role of stem cells in acupuncture treatment for neurodegenerative diseases: a literature review of basic studies

This review reports on recent findings concerning the effects of acupuncture and electroacupuncture (EA) on stem cell mobilization and differentiation, in particular with regard to neurogenesis. Traditional Chinese acupuncture has a history of over 2,500 years and is becoming more popular worldwide. Evidence has demonstrated that acupuncture may be of benefit in stroke rehabilitation, parkinsonism, dementia, and depression. This article reviews recent studies concerning the effects of acupuncture/EA on stem cell mobilization and on progenitor cell proliferation in the CNS. The reviewed evidence indicates that acupuncture/EA has beneficial effects in several neurodegenerative diseases, and it may prove to be a nondrug method for mobilizing stem cells in the CNS.

Acupuncture effect and central autonomic regulation

Acupuncture is a therapeutic technique and part of traditional Chinese medicine (TCM). Acupuncture has clinical efficacy on various autonomic nerve-related disorders, such as cardiovascular diseases, epilepsy, anxiety and nervousness, circadian rhythm disorders, polycystic ovary syndrome (PCOS) and subfertility. An increasing number of studies have demonstrated that acupuncture can control autonomic nerve system (ANS) functions including blood pressure, pupil size, skin conductance, skin temperature, muscle sympathetic nerve activities, heart rate and/or pulse rate, and heart rate variability. Emerging evidence indicates that acupuncture treatment not only activates distinct brain regions in different kinds of diseases caused by imbalance between the sympathetic and parasympathetic activities, but also modulates adaptive neurotransmitter in related brain regions to alleviate autonomic response. This review focused on the central mechanism of acupuncture in modulating various autonomic responses, which might provide neurobiological foundations for acupuncture effects.

The Influence of Electro-Acupuncture Stimulation to Female Constipation Patients

This study aims to examine electro-acupuncture stimulation (EA) assisted therapy with analysis of heart rate variability to understand autonomic nervous activity variability (ANAV) and to track the changes in female patients with constipation. The average ages were 42±12 years old. The participants were divided by a single-blind and randomized trial into two groups: the electro-acupuncture-point group, and the non-electro-acupuncture-point group. Both of the groups had eight treatments, once a week. For the electro-acupuncture (EA) group, needles were inserted into their Zusunli (ST36), Shangiuxu (ST37), Tiensu (ST25), Shueidao (ST28), Guanyuan (CV4) and Qihai (CV6) points. For the sham electro-acupuncture (SA) group, needles were inserted into acu-points that were not the ones mentioned for the EA group. While inserting needles, needles were inserted lightly into the participants' skin and removed quickly (mock Transcutaneous Electrical Nerve Stimulation, TENTS). After an eight-week treatment period, the autonomic nervous system activities of the SA group did not show significant differences in their heart rate variability. However, the autonomic nervous system activities of the EA group had continuously increased after each session. The normalized high frequency powers (nHFP) of their autonomic nervous system activities were 26.79 in the first week, and they increased to 32.28 in the fourth week. In the eighth week, their nHFP had increased to 37.60 (p < 0.05). The normalized low frequency power (nLFP) was 30.81 in the first week. However, it decreased to 25.98 after three weeks of treatment. After the eight-week treatment period, the nLFP decreased to 24.84 (p < 0.05). After the eight-week treatment, the control group did not appear to undergo any physiological change, while the constipation had been improved for the experimental group. It was found that the activation of parasympathetic nervous system in the experimental group increased after the eight-week treatment. The effects of such a result on the enhancement of the activation of parasympathetic nervous system and the improvement of constipation should be further discussed.

A comparison between acupuncture versus zolpidem in the treatment of primary insomnia

BACKGROUND

To determine the relative efficacy of acupuncture and zolpidem in the treatment of primary insomnia, we administered a sleep quality scale to thirty-three patients with primary insomnia randomly chosen to receive one of the two therapies at a psychosomatic clinic.

METHODS

A study in the psychosomatic clinic at a teaching hospital in southern Taiwan from November 2007 to November 2008. The 19 patients in acupuncture group underwent one acupuncture session a week. The 14 patients in the control group took zolpidem 1# (10mg) every night. Members of both groups returned to our clinic once a week for four weeks. The main outcome measure was the Pittsburgh Sleep Quality Index (PSQI).

RESULTS

Both groups were found to have improved significantly. Using generalized estimating equation analysis to test the variance with group and time as factors, we found both groups improved over time at a similar rate (p=0.79). In regression analysis, setting the fourth total PSQI score to zero, the baseline PSQI score was 4.13 (p<0.001), the second score 1.32 (p=0.005), and the third 1.49 (p=0.03); men had a higher PSQI score 1.56 than women (p=0.02); the increasing age of one year would have lower PSQI score 0.08 (p<0.001) and increasing educational level of one year which would decrease PSQI score 0.25 (p=0.007).

CONCLUSIONS

Acupuncture might be used as an alternative strategy compared to zolpidem for the treatment of primary insomnia.

Differential autonomic response to acupuncture at wood and metal of five-shu acupoints

OBJECTIVES

The study examined differential autonomic nervous responses to acupuncture stimulation at the wood points ([Formula: see text]) and the metal points ([Formula: see text]) among the five-shu points of the Pericardium and Triple Energizer Meridian.

DESIGN

This was a crossover study of different acupuncture points with randomized order.

SUBJECTS

The study subjects were 30 healthy female volunteers (22.8 ± 2.6 years old).

INTERVENTIONS

The acupuncture sessions were carried out over four sessions at 2-5-day intervals at the same time of day with one of the four acupoints: the wood distal point (Zhongchong, PC9), metal distal point (Zhongzhu, TE3), wood proximal point (Jianshi, PC5), and metal proximal point (Guanchong, TE1) on the left hand. After 5 minutes' rest (Pre-Acup), acupuncture needles were inserted, manipulated promptly, and were retained for 20 minutes followed by 5 minutes' rest (Post-Acup).

MAIN OUTCOME MEASURES

Heart rate variability, skin conductance response, respiration rate, and peripheral skin temperature were measured.

RESULTS

For the normalized low-frequency band of heart rate variability, there was a statistically significant increase during Acup and Post-Acup at the PC9 and TE3 wood points compared with Pre-Acup. Statistically significant decreases for PC5 and TE1 were evident at the metal points. Skin conductance response and peripheral skin temperature, which are indicative of sympathetic activity and blood flow, respectively, were significantly induced at PC9 during Acup compared to Pre-Acup.

CONCLUSIONS

The wood points PC9 and TE3 increase sympathetic activity; and the metal points TE1 and PC5 increase the parasympathetic activity. The effect of acupuncture on the autonomic nervous system differs between the wood and the metal points.

Intradermal Acupuncture on Shen-Men and Nei-Kuan Acupoints Improves Insomnia in Stroke Patients by Reducing the Sympathetic Nervous Activity: A Randomized Clinical Trial

This study is a double-blind randomized controlled trial on the effect of intradermal acupuncture on insomnia after stroke. Hospitalized stroke patients with insomnia were enrolled in the study and were randomly assigned to either a real intradermal acupuncture group (RA group) or a sham acupuncture group (SA group). The RA group received intradermal acupuncture on Shen-Men (He-7) and Nei-Kuan (EH-6) for three days, and the SA group received sham acupuncture on the same points. The effect of acupuncture on insomnia was measured using Insomnia Severity Index (ISI) and Athens Insomnia Scale (AIS) at baseline and three days after treatment. To assess the effect of acupuncture on the autonomic nervous function, the subjects' blood pressure and heart rate variability were monitored. Fifty-two subjects (27 in the RA group and 25 in the SA group) were included in the final analysis. The insomnia-related scales ISI and AIS showed greater improvement of insomnia in the RA group than in the SA group. Moreover, there is a greater reduction of the number of non-dippers and a greater decrease of the LF/HF ratio (heart rate variability) in the RA group than in the SA group. These results indicate that sympathetic hyperactivities were stabilized in the RA group. It can thus be concluded that intradermal acupuncture on Shen-Men and Nei-Kuan is a useful therapeutic method for post stroke-onset insomnia as it reduces sympathetic hyperactivities.

Electroacupuncture Induces Differential Effects between Yin and Yang: A Study using Cutaneous Blood Flow and Temperature Recordings of the Hand's Dorsum and Palm

The underlying theory of traditional Chinese Medicine (TCM) considers that Yin and Yang are in the opposition with each other and play different roles in physiological responses. Several studies have reported that electroacupuncture (EA) produces a greater effect than manual acupuncture (MA), and that the effect of EA is similar to transcutaneous electric nerve stimulation (TENS). Therefore, the purpose of the present study was to investigate the differences between Yin and Yang induced by acupuncture. A total of 20 healthy volunteers were studied. The cutaneous blood flow and temperature were recorded by a laser doppler perfusion and temperature monitoring system on the dorsum and palm of the right hand. Four sessions of sham acupuncture (SA), MA, 2 Hz EA, and 2 Hz TENS were bilaterally applied to Zusanli (ST36) and Shangjuxu (ST37) acupoints. Each of the subjects received four sessions in a random manner. The treatment interval was at least three days between sessions in order to prevent overlapping residual effects. Each of the four sessions was divided into pre-acupuncture period (BP), acupuncture period (AP), and post-acupuncture (PP) periods. Each treatment period was 15 min. Results indicated that the cutaneous blood flow recorded from the palm of the hand were greater than that recorded from the dorsum at the pre-acupuncture period; while the difference in the cutaneous temperature from the dorsum of the hand between AP and BP was greater in the 2 Hz EA session than in the SA and MA sessions. In conclusion, the results of the present study were consistent with the underlying theory of TCM that considers the fundamental differences between Yin and Yang.

The antinociceptive effect of electroacupuncture at different depths of acupoints and under the needling surface

Background

The stimulation of acupoints along the meridians, but not the non-acupoints outside of the meridians, produces analgesia. Although the acupoint is defined at the body surface, the exact location of the acupoints is not known. This study aims to examine whether the intensity and duration of the analgesic effect of electroacupuncture (EA) at the Zusanli (ST36) and Sanynjiao acupoints (SP6) change according to the depth of the stimulation.

Methods

Ninety-six male Wistar rats classified as responders were arbitrarily allocated into 16 groups of six rats each. Six groups received EA with uninsulated acupuncture needles (type I) or needles that were immersed in varnish and had the varnish circularly peeled 0.2 mm from the tip (type II), 0.2 mm at 3 mm (type III) or 5 mm (type IV) from the tip, or 0.2 mm at 5 and 1 mm from the tip (type V), or EA sham for 20 min. Five groups received injection of formalin into the acupoint bilaterally at 5 mm or 1 mm deep into ST36, 5 mm below ST36 but inserting the needle at 45° to the skin surface, or 5 mm deep into non-acupoints. The remaining groups received intraplantar injection of saline, 1% or 2.5% formalin. The analgesic effects were measured by the rat tail-flick test.

Results

The bilateral stimulation of ST36 and SP6 by uninsulated or insulated needles produced analgesia in the rat tail-flick test. The stronger and longer lasting effects occurred after EA with the types I and V needles, or injection of formalin 5 mm deep into ST36. The remaining needles produced weaker and shorter lasting effects. Slow analgesic effect also occurred after formalin injection at 1 mm or 5 mm below ST36 by inserting the needle at 45° to the skin surface.

Conclusion

The experimental results suggest that the efficacy of the EA stimulation depends on the spatial distribution of the current density under the needling surface rather than only the acupoint or the depth of needling.

Electroacupuncture-induced cholinergic nerve activation enhances the hypoglycemic effect of exogenous insulin in a rat model of streptozotocin-induced diabetes

The aim of this study is to explore the mechanisms by which electroacupuncture (EA) enhances the hypoglycemic effect of exogenous insulin in a streptozotocin- (STZ-) diabetic rats. Animals in the EA group were anesthetized and subjected to the insulin challenge test (ICT) and EA for 60 minutes. In the control group, rats were subjected to the same treatment with the exception of EA stimulation. Blood samples were drawn to measure changes in plasma glucose, free fatty acids (FFA), and insulin levels. Western blot was used to assay proteins involved in insulin signaling. Furthermore, atropine, hemicholinium-3 (HC-3), and Eserine were used to explore the relationship between EA and cholinergic nerve activation during ICT. EA augmented the blood glucose-lowering effects of EA by activating the cholinergic nerves in STZ rats that had been exposed to exogenous insulin. This phenomenon may be related to enhancement of insulin signaling rather than to changes in FFA concentration.

Electroacupuncture at the Zusanli (ST-36) Acupoint Induces a Hypoglycemic Effect by Stimulating the Cholinergic Nerve in a Rat Model of Streptozotocine-Induced Insulin-Dependent Diabetes Mellitus

Animal studies have shown that electroacupuncture (EA) at Zusanli (ST-36) and Zhongwan (CV-12) acupoints reduces plasma glucose concentrations in rats with type II diabetes. However, whether EA reduces plasma glucose levels in type I diabetes is still unknown. In this study, we explore the various non-insulin-dependent pathways involved in EA-induced lowering of plasma glucose. Streptozotocin (STZ) (60 mg kg⁻¹, i.v.) was administered via the femoral vein to induce insulin-dependent diabetes in non-adrenalectomized and in adrenalectomomized rats. EA (15 Hz) was applied for 30 min to bilateral ST-36 acupoints after administration of Atropine (0.1 mg kg⁻¹ i.p.), Eserine (0.01 mg kg⁻¹ i.p.), or Hemicholinium-3 (5 μg kg⁻¹ i.p.) in non-adrenalectomized rats. Rats administered acetylcholine (0.01 mg kg⁻¹ i.v.) did not undergo EA. Adrenalectomized rats underwent EA at bilateral ST-36 acupoints without further treatment. Blood samples were drawn from all rats before and after EA to measure changes in plasma glucose levels. Expression of insulin signaling proteins (IRS1, AKT2) in atropine-exposed rats before and after EA was measured by western blot. Atropine and hemicholinium-3 completely blocked the plasma glucose lowering effects of EA, whereas eserine led to a significant hypoglycemic response. In addition, plasma glucose levels after administration of acetylcholine were significantly lower than the fasting glucose levels. In STZ-adrenalectomized rats, EA did not induce a hypoglycemic response. EA stimulated the expression of IRS1 and AKT2 and atropine treatment blocked the EA-induced expression of those insulin signaling proteins. Taken together, EA at the ST-36 acupoint reduces plasma glucose concentrations by stimulating the cholinergic nerves.

Acupuncture analgesia: a review of its mechanisms of actions

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.

Intradermal acupuncture on shen-men and nei-kuan acupoints in patients with insomnia after stroke

This is the first study that focuses on the effects of intradermal acupuncture on insomnia after stroke. We enrolled hospitalized stroke patients with insomnia and assigned them into a real intradermal acupuncture group (RA group) or a sham acupuncture group (SA group) by randomization. The RA group received intradermal acupuncture on shen-men (He-7) and nei-kuan (EH-6) for 2 days, and the SA group received sham acupuncture on the same points. The effectiveness was measured by the Morning Questionnaire (MQ), Insomnia Severity Index (ISI), and Athens Insomnia Scale (AIS). These scales were examined by an independent, blinded neurologist before, and 1 and 2 days after treatment, repeatedly. Thirty subjects (15 in the RA group and 15 in the SA group) were included in the final analysis. The RA group showed more improvement on insomnia than the SA group. Repeated measures analysis detected that there were significant between-subjects effects in the MQ, the ISI and the AIS. In conclusion, we suggest that intradermal acupuncture on shen-men and nei-kuan is a useful treatment for post stroke-onset insomnia.

Low and high frequency acupuncture stimulation inhibits mental stress-induced sweating in humans via different mechanisms

The effects of acupuncture stimulation at 5 Hz and 100 Hz on mental stress-induced sweating were analyzed, and the mechanisms involved were examined using the rate of sweat expulsion as an estimate of central sudomotor outflow. Mental arithmetic was imposed on 25 young healthy volunteers for 2 min before, during and after the stimulation. Acupuncture stimulation was delivered to either the Zusanli (leg) or Hegu (hand) acupoint, and the sweat rate was measured quantitatively during mental arithmetic on the palm or the sole, respectively. When stimulation at 5 Hz was applied to the Zusanli acupoint, the palmar sweat rate (paSR), rate of sweat expulsion (Fsw) and paSR/Fsw were reduced during the stimulation, whereas when it was applied to the Hegu acupoint, plantar SR (plSR) and Fsw were reduced, but plSR/Fsw was not altered. When stimulation at 100 Hz was applied to Zusanli, paSR and paSR/Fsw were reduced, but Fsw was unchanged whereas when it was applied to Hegu, neither plSR, Fsw nor plSR/Fsw was altered. The results suggest that acupuncture stimulation at 5 Hz affects both the supraspinal rhythm-generating mechanism and the mechanisms situated below (probably the spinal cord), whereas stimulation at 100 Hz only affects the mechanisms below the rhythm-generating mechanism. Thus, acupuncture stimulation at 5 Hz and at 100 Hz may reduce mental stress-induced sweating through different mechanisms.

Review article: therapeutic roles of acupuncture in functional gastrointestinal disorders

Acupuncture has been practiced empirically in China for several millennia, and is being increasingly accepted by practitioners and patients worldwide. Functional gastrointestinal disorders are common in clinical gastroenterology. The prevalence of one or more functional gastrointestinal disorders is estimated to be as high as 70% in general population using Rome diagnostic criteria. Since functional gastrointestinal disorders are diagnosed based on symptoms and the exact aetiologies for most of functional gastrointestinal disorders are not completely known, it is not unusual that the treatment for these disorders is unsatisfactory and alternative therapies are attractive to both patients and practitioners. During the latest decades, a considerable number of studies have been performed on acupuncture for the treatment of functional gastrointestinal disorders and underlying mechanisms. In this article, we reviewed available data in the literature on the applications and mechanisms of acupuncture for the treatment of functional gastrointestinal disorders, including functional oesophageal disorders, nausea and vomiting, functional dyspepsia, irritable bowel syndrome, constipation, etc. A summary is provided based on the quality and quantity of published studies regarding the efficacy of acupuncture in treating these various disorders. In addition, the methodology of acupuncture is also introduced.

Analgesic effect of electric stimulation of peripheral nerves with different electric frequencies using the formalin test

Although electroacupuncture (EA) has been widely used to treat pain, the optimal frequency of EA therapy remains unclear. The study sought to determine the effect of different EA frequencies in a Sprague-Dawley (SD) rat model of pain. Electric stimulation (ES) at frequencies of 2 Hz, 15 Hz or 100 Hz was applied to the ipsilateral or contralateral sciatic nerve of the injected hindpaw of SD rats. Formalin (50 microl, 5%) was subcutaneously injected into the plantar surface of the left hindpaw to induce a nociceptive response. Behavior, including licking and biting, was observed to have two distinct periods, an early phase during the first 5 mins and a late phase from 21-35 mins after injection. The total biting or licking count served as an Indicator of nociceptive response. Our results indicate that ES of the ipsilateral sciatic nerve at a frequency of 2 Hz or 15 Hz reduced the nociceptive responses in both the early and the late phases of the formalin test, whereas ES at 2 Hz had greater antinociceptive effect than ES at 15 Hz in the early phase. No similar analgesic effect in the early phase was observed for ES at 100 Hz. Both pretreatment with ES at 2 Hz and naloxone (3 mg/kg, s.c.) produced a greater antinociceptive response in the late phase than when ES at 2 Hz was delivered immediately after formalin administration. In addition, ES of the neck muscle or contralateral sciatic nerve at a frequency of 2 Hz also decreased licking and biting activity in both phases. The results of this study indicate that different analgesic mechanisms are involved in the response to ES at frequencies of 2 Hz, 15 Hz and 100 Hz, and that ES at 2 Hz has a greater analgesic effect on formalin-induced nociceptive response, especially when it is delivered prior to the onset of pain. The analgesic effect of ES may be mediated via a central origin in the supraspinal level. These findings suggest that 2 Hz may be a good frequency selection for clinical EA applications in analgesia, and that pretreatment with EA at 2 Hz may be an effective method to treat post-operative pain.

Pulse type classification by varying contact pressure

We introduced a new technique of quantification of pulse characteristics in connection with contact pressure. We provided data only for illustrative purposes, deferring statistical analysis of samples of a larger population. This quantification can be useful for diagnostic purposes; for example, by detecting changes of the three quantities according to the health condition or particular disease of a patient, or by analyzing correlations among these quantities and other physiological variables.