Effects of acupuncture on vasopressin-induced emesis in conscious dogs

The efficacy and safety of complementary and alternative medicine in the treatment of nausea and vomiting during pregnancy: A systematic review and meta-analysis

Background

Complementary and alternative medicine (CAM) therapies are widely used for nausea and vomiting during pregnancy (NVP) due to the limitations of conventional medicine. However, their efficacy and safety remain controversial. Therefore, this meta-analysis was performed to assess the improvement of CAM therapy on NVP.

Methods

Randomized controlled trials (RCTs) were searched for where the trial group was CAM and the control group was a conventional medicine or a placebo for NVP. This was done via 8 databases, including PubMed, EMBASE, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang, SinoMed, and VIP, from inception to October 25, 2022. The Grades of Recommendation, Assessment, Development and Evaluation (GRADE) was used to assess the quality of evidence. The Stata 15.0 software was used to perform the meta-analysis.

Results

Thirty-three RCTs were included in this study. The acupuncture treatment was superior to conventional medicine at the effective rate [RR = 1.71, 95% CI (1.02, 2.86), P = 0.042; Low-quality evidence]. Ginger had more significant effects than conventional medicine at the Rhodes index [WMD = −0.52, 95% CI (−0.79, −0.24), P ≤ 0.001; Moderate-quality evidence] and it had the same effect as drugs to relieve vomiting [SMD = 0.30, 95% CI (−0.12, 0.73), P = 0.160; Low-quality evidence]. Compared with placebo, ginger had a higher effective rate [RR = 1.68, 95% CI (1.09, 2.57), P = 0.018; Low-quality evidence], and lower Visual analog scale (VAS) of Nausea [WMD = −1.21, 95% CI (−2.34, −0.08), P = 0.036; Low-quality evidence]. Ginger had the same antiemetic effect as placebo [WMD = 0.05, 95% CI (−0.23, 0.32), P = 0.743; Low-quality evidence]. Acupressure was superior to conventional medicine at the reduction of antiemetic drugs [SMD = −0.44, 95% CI (−0.77, −0.11), P = 0.008; Low-quality evidence], and at the effective rate [RR = 1.55, 95% CI (1.30, 1.86), P ≤ 0.001; Low-quality evidence]. Acupressure had the same effect as placebo at the effective rate [RR = 1.25, 95% CI (0.94, 1.65), P = 0.124; Low-quality evidence]. Overall, CAM therapy was safer than conventional medicine or a placebo.

Conclusion

The results showed that CAM therapies were able to alleviate NVP. However, due to the low quality of existing RCTs, more RCTs with large sample sizes are needed to validate this conclusion in the future.

Ondansetron in dogs with nausea associated with vestibular disease: A double-blinded, randomized placebo-controlled crossover study

Background

Nausea and emesis can be, among other signs, common manifestations of acute vestibular system dysfunction in dogs. Currently, antiemetic drugs, such as maropitant and metoclopramide, are used commonly, but do not appear to control nausea. A non‐placebo‐controlled preliminary study suggested good efficacy of 5‐HT3‐receptor antagonists, such as ondansetron, against nausea in dogs with vestibular syndrome.

Objectives

To assess and confirm the effect of ondansetron on behavior suggestive of nausea in dogs with vestibular syndrome.

Animals

Fourteen dogs with vestibular syndrome and clinical signs of nausea presented to a neurology service.

Methods

Placebo‐controlled, double‐blinded, crossover study. Behavioral assessment was performed hourly for 4 hours using an established numerical rating scale. The criteria salivation, lip licking, vocalization, restlessness, lethargy, and general nausea were scored. The occurrence of emesis was recorded. After scoring at T0 (pre‐dose) and T2 (2 hours post‐dose) either ondansetron (0.5 mg/kg) or placebo was injected IV. Two hours post‐dose, treatments were switched. Blood samples were collected to measure serum arginine vasopressin (AVP) concentration, which previously has been shown to correlate with clinical signs of nausea.

Results

Clinical resolution of nausea was observed 1 hour after administration of ondansetron, whereas serum AVP concentration decreased 4 hours after ondansetron administration.

Conclusion and Clinical Importance

Administration of ondansetron IV is beneficial for dogs with nausea secondary to acute vestibular syndrome. Ondansetron substantially and rapidly decreased clinical signs of nausea behavior and stopped emesis.

Effects of Moxibustion on Stress-Induced Delayed Gastric Emptying via Somatoautonomic Reflex in Rats

Objective: Moxibustion (MOX) is used to treat a wide variety of disorders, including those with gastric symptoms. However, the exact mechanisms underlying the beneficial effects of MOX are unknown. The purpose of this study was to investigate if application of indirect MOX (iMOX) to ST 36 reduces restraint stress (RS)-induced alteration in gastric responses of conscious rats, and if a somatoautonomic reflex mediates gastric emptying (GE). Materials and Methods: One group of rats was fed solid food after 24 hours of fasting. Immediately after food ingestion. These rats were subjected to RS. Ninety minutes after feeding, the rats were euthanized, and their gastric contents were removed to calculate GE. iMOX had been performed at ST 36 bilaterally throughout the stress loading. To investigate if vagal-nerve activity was involved in mediating the stress-induced alterations of GE by iMOX, atropine was intraperitoneally administered to other rats just before initiating RS; bilateral truncal vagotomy had been performed on day 14 before GE measurement. Results: RS delayed GE significantly (42.9 ± 5.8%)in stressed rats, compared to nonstressed rats (68.7 ± 1.8%). iMOX at ST 36 reduced stress-induced inhibition of GE significantly (67.1 ± 2.4%). MOX-mediated reduction of GE disappeared upon atropine injection and vagotomy. Conclusions: RS-induced delayed GE may be ameliorated by iMOX at ST 36. Somatoautonomic, reflex-induced vagal-nerve activity helps mediate the stimulatory effects of iMOX on RS-induced delayed GE. As a complementary and alternative medicine, iMOX may also be advantageous for patients with gastric disorders, such as functional dyspepsia.

Inner Ear Arginine Vasopressin-Vasopressin Receptor 2-Aquaporin 2 Signaling Pathway Is Involved in the Induction of Motion Sickness

It has been identified that arginine vasopressin (AVP), vasopressin receptor 2(V2R), and the aquaporin 2 (AQP2) signaling pathway in the inner ear play important roles in hearing and balance functions through regulating the endolymph equilibrium; however, the contributions of this signaling pathway to the development of motion sickness are unclear. The present study was designed to investigate whether the activation of the AVP-V2R-AQP2 signaling pathway in the inner ear is involved in the induction of motion sickness and whether mozavaptan, a V2R antagonist, could reduce motion sickness. We found that both rotatory stimulus and intraperitoneal AVP injection induced conditioned taste aversion (a confirmed behavioral index for motion sickness) in rats and activated the AVP-V2R-AQP2 signaling pathway with a responsive V2R downregulation in the inner ears, and AVP perfusion in cultured epithelial cells from rat endolymphatic sacs induced similar changes in this pathway signaling. Vestibular training, V2R antagonist mozavaptan, or PKA inhibitor H89 blunted these changes in the V2R-AQP2 pathway signaling while reducing rotatory stimulus- or DDAVP (a V2R agonist)-induced motion sickness in rats and dogs. Therefore, our results suggest that activation of the inner ear AVP-V2R-AQP2 signaling pathway is potentially involved in the development of motion sickness; thus, mozavaptan targeting AVP V2Rs in the inner ear may provide us with a new application option to reduce motion sickness. SIGNIFICANCE STATEMENT: Motion sickness affects many people traveling or working. In the present study our results showed that activation of the inner ear arginine vasopressin-vaspopressin receptor 2 (V2R)-aquaporin 2 signaling pathway was potentially involved in the development of motion sickness and that blocking V2R with mozavaptan, a V2R antagonist, was much more effective in reducing motion sickness in both rat and dog; therefore, we demonstrated a new mechanism to underlie motion sickness and a new candidate drug to reduce motion sickness.

Psycho-physiological mechanism of energy transfer in the human body: myth or reality?

The authors consider the existence of an energy transfer system (ETS) in the human body and its consequenc-es for health, performing a review of the available literature and studies. The article is an attempt to describe the possible psychophysiological mechanism of ETS (i.e. mechanism of transmission of stimuli in connective tissue) based on biochemical reactions, which was first described in Eastern Medicine a long time ago. Some previously reported results suggest that it is possible to modulate the psychophysiological effects on the con-nective tissue, and that the internal ETS can be activated not only through internal acupoints but also through breath self-regulation techniques. Among the people specialized in such breathing are martial art fighters. In a very preliminary pilot study we investigate four cases in a Vietnamese Thiên Môn Đạo (TMD) group, where breathing techniques result in cardiovascular and blood pressure changes, which can indirectly suggest activa-tion of ETS. An additional energy system in the human body is postulated. However, future research is serious-ly needed. Findings could be applicable e.g. in cardiac rehabilitation programs.

The effect of aquapuncture at Pericardium 6 (PC-6) on dexmedetomidine-induced nausea and vomiting in cats

OBJECTIVE

To determine the effect of aquapuncture at acupuncture point Pericardium 6 (PC-6) on the incidence of dexmedetomidine-induced vomiting and nausea in cats.

STUDY DESIGN

Randomized, prospective, crossover study.

ANIMALS

A group of 22 cats, 14 females and eight males, aged 1-12 years and weighing 3.8-5.9 kg.

METHODS

Each cat was administered treatments in random order at ≥1 week intervals. For treatment (DEX-A), cats were administered PC-6 stimulation by aquapuncture (0.25 mL/250 μg vitamin B12 injection subcutaneously at PC-6). After 30 minutes, dexmedetomidine (10 μg kg^-1) was administered intramuscularly (IM). For control treatment (DEX), cats were administered only dexmedetomidine (10 μg kg^-1) IM. Incidence of vomiting, number of vomiting episodes and time to first vomiting were recorded by an observer unaware of treatment allocation. At 30 minutes after dexmedetomidine administration, atipamezole (0.1 mg kg^-1) was injected IM. Behavior was video recorded and later scored by two observers for clinical signs of nausea. A regression model (analysis of covariance) was used to detect the influence of aquapuncture on vomiting and nausea. Significance was set at p < 0.05.

RESULTS

Of 21 cats, 18 (85%) and 16 cats (76%) vomited in DEX-A and DEX, respectively. There was no significant difference in the incidence of vomiting (p = 0.55), number of vomiting episodes (p = 0.55), mean time to vomit (p = 0.88) or nausea score (p = 0.51) between DEX-A and DEX.

CONCLUSIONS AND CLINICAL RELEVANCE

PC-6 aquapuncture did not reduce the incidence of dexmedetomidine-induced vomiting or severity of nausea in cats.

Non-invasive High Frequency Median Nerve Stimulation Effectively Suppresses Olfactory Intensity Perception in Healthy Males

Median nerve stimulation (MNS) had been performed in the existing literature to alleviate symptoms of nausea and vomiting. The observed facilitative effects are thought to be mediated by the vagal pathways, particularly the vagus nerve (VN) brainstem nuclei of the dorsal motor nucleus of vagus and nucleus tractus solitarius (DMV-NTS). Sense of smell is one of the major sensory modalities for inducing vomiting and nausea as a primary defense against potentially harmful intake of material. This study aimed to test effects of non-invasive, high and low frequency MNS on human olfactory functioning, with supplementary exploration of the orbitofrontal cortex (OFC) using near-infrared spectroscopy (NIRS). Twenty healthy, male, adults performed supra-threshold odor intensity tests (labeled magnitude scale, LMS) for four food-related odorant samples (presented in three different concentrations) before and after receiving high-, low frequency MNS and placebo (no stimulation), while cortical activities in the OFC was monitored by the NIRS. Data of the NIRS and LMS test of separate stimulation parameters were statistically analyzed using mixed-model analysis of variance (ANOVA). Only the high frequency MNS showed effects for suppressing the intensity perception of the moderate concentration of Amyl Acetate (p:0.042) and strong concentration of Isovaleric Acid (p:0.004) and 1-Octen-3-ol (p:0.006). These behavioral changes were coupled with significant changes in the NIRS recordings of the left (p:0.000) and right (p:0.003) hemispheric orbitofrontal cortices. This is the first study that applied non-invasive, high frequency MNS to suppress the supra-threshold odor ratings of specific concentrations of odors. The vagal networks are potential relays of MNS to influence OFC. Results from the current article implore further research into non-invasive, high frequency MNS in the investigation of its modulatory effects on olfactory function, given its potential to be used for ameliorating nausea and malnutrition associated with various health conditions.

Chemotherapy-Induced Pica in Rats Reduced by Electroacupuncture

OBJECTIVES

Acupuncture or electroacupuncture (EA) has been applied for treating chemotherapy-induced emesis with limited success. The aims of this study were to investigate the anti-emetic effect of EA and to explore underlying anti-emetic mechanisms.

MATERIALS AND METHODS

Rats were chronically implanted with a pair of stainless steel leads at acupoint pericardium 6 (PC6). Effects of EA with different parameters on cisplatin-induced nausea were assessed by pica (intake of kaolin, a surrogate of nausea in species without vomiting reflex). C-fos expressions in the area postrema (AP) and nucleus tractus solitarii (NTS) were analyzed. Subdiaphragmatic vagotomy was used to study involvement of the vagal pathway.

RESULTS

1) EA at 20 Hz/0.6 msec reduced kaolin intake in the first and second days after cisplatin injection compared with the sham-EA group (first day: 1.0 ± 0.2 vs. 1.9 ± 0.3 g, p = 0.017; second day: 0.4 ± 0.2 vs.1.1 ± 0.3 g, p = 0.010). However, EA at 10 Hz/1.2 msec was ineffective on both days. 2) Subdiaphragmatic vagotomy significantly reduced cisplatin-induced kaolin intake (1.1 ± 0.3 vs. 2.2 ± 0.3 g, p = 0.014) and also blocked the inhibitory effect of EA on kaolin intake in the first day. 3) Cisplatin significantly increased the expression of c-fos in the NTS and AP. Vagotomy greatly reduced c-fos expression in both NTS and AP. EA reduced the cisplatin-induced c-fos expression in the AP but not the NTS.

CONCLUSIONS

EA at PC6 with appropriate parameters has an inhibitory effect on cisplatin-induced nausea. The anti-emetic effect of the EA is centrally medicated involving the AP via the vagal pathway as well as the potential effect on AP by reducing the release of hormones.

AVP modulation of the vestibular nucleus via V1b receptors potentially contributes to the development of motion sickness in rat

BACKGROUND

Arginine vasopressin (AVP) is considered to be an etiologic hormone in motion sickness (MS). The present study was designed to investigate whether individual differences in AVP expression in the paraventricular nucleus (PVN) and in modulation on the vestibular nucleus (VN) are involved in MS. Systemic application or microinjection of AVP into rat VN and rotatory stimulus were used to induce conditioned taste aversion (CTA) to 0.15 % saccharin sodium solution as a model of MS.

RESULTS

Intra-VN use of SSR149415, an antagonist of V1b receptors (V1bRs), blunted CTA. AVP inhibited Ca(2+) influxes through L-type Ca(2+) channels and NMDA receptor channels in cultured VN neurones, but antagonised by SSR149415. More AVP and V1bRs were expressed respectively in the PVN and VN after rotatory stimulus, especially in rats susceptible to MS. In the VN, AVP content was low, the AVP mRNA was less expressed, a few AVP-positive fibres were sparsely distributed, and fewer AVP/synaptophysin-positive terminals were identified. Almost no fluoro-ruby-labelled AVP-positive neurones in the PVN were found with retrograde tracing from the VN. SNP analysis of the reported 9 sites of the AVP gene showed significant difference between the groups susceptible and insusceptible to MS at the site rs105235842 in the allele frequencies and genotypes. However, there was not any difference between these two groups in the SNP of the reported 38 sites of V1bR gene.

CONCLUSIONS

AVP, through its modulatory, possibly humoral action on the VN neurones via the mediation of V1bR, may contribute to the development of motion sickness in rats; AVP gene polymorphisms may contribute to the individual difference in the responsive expression of AVP in the PVN; and higher expressions of AVP in the PVN and V1bRs in the VN may contribute to the development of motion sickness in rats after vestibular stimulation.

Effects of maropitant, acepromazine, and electroacupuncture on vomiting associated with administration of morphine in dogs

OBJECTIVE

To evaluate effects of maropitant, acepromazine, and electroacupuncture on morphine-related signs of nausea and vomiting in dogs and assess sedative effects of the treatments.

DESIGN

Randomized controlled clinical trial.

ANIMALS

222 dogs.

PROCEDURES

Dogs received 1 of 6 treatments: injection of saline (0.9% NaCl) solution, maropitant citrate, or acepromazine maleate or electroacupuncture treatment at 1 acupoint, 5 acupoints, or a sham acupoint. Morphine was administered after 20 minutes of electroacupuncture treatment or 20 minutes after injectable treatment. Vomiting and retching events and signs of nausea and sedation were recorded.

RESULTS

Incidence of vomiting and retching was significantly lower in the maropitant (14/37 [37.8%]) group than in the saline solution (28/37 [75.7%]) and sham-acupoint electroacupuncture (32/37 [86.5%]) groups. The number of vomiting and retching events in the maropitant (21), acepromazine (38), 1-acupoint (35), and 5-acupoint (34) groups was significantly lower than in the saline solution (88) and sham-acupoint electroacupuncture (109) groups. Incidence of signs of nausea was significantly lower in the acepromazine group (3/37 [8.1%]) than in the sham-acupoint group (15/37 [40.5%]). Mean nausea scores for the saline solution, maropitant, and sham-acupoint electroacupuncture groups increased significantly after morphine administration, whereas those for the acepromazine, 1-acupoint electroacupuncture, and 5-acupoint electroacupuncture groups did not. Mean sedation scores after morphine administration were significantly higher in dogs that received acepromazine than in dogs that received saline solution, maropitant, and sham-acupoint electroacupuncture treatment.

CONCLUSIONS AND CLINICAL RELEVANCE

Maropitant treatment was associated with a lower incidence of vomiting and retching, compared with control treatments, and acepromazine and electroacupuncture appeared to prevent an increase in severity of nausea following morphine administration in dogs.

Nausea: current knowledge of mechanisms, measurement and clinical impact

Nausea is a subjective sensation, which often acts as a signal that emesis is imminent. It is a widespread problem that occurs as a clinical sign of disease or as an adverse effect of a drug therapy or surgical procedure. The mechanisms of nausea are complex and the neural pathways are currently poorly understood. This review summarises the current knowledge of nausea mechanisms, the available animal models for nausea research and the anti-nausea properties of commercially available anti-emetic drugs. The review also presents subjective assessment and scoring of nausea. A better understanding of the underlying mechanisms of nausea might reveal potential clinically useful biomarkers for objective measurement of nausea in species of veterinary interest.

Simple acupoints prescription flow chart based on meridian theory: a retrospective study in 102 dogs

To help the clinicians prescribe acupoints easily and effectively, we developed one simple flow chart to select acupoints. This study aimed to evaluate the usefulness of flow chart to select acupoints in dogs. Total 102 dogs showing intervertebral disc disease (IVDD) (n = 12), vomiting (n = 11), diarrhea (n = 2), abdominal pain (n = 5), cough (n = 66), or epilepsy (n = 6) received acupuncture treatment according to the chart, and its outcomes were evaluated as regards clinical symptoms, duration, treatment numbers, and recovery time. Dogs (8/8) with IVDD from grades I to III recovered over periods of 5 days to 6 weeks after 1–12 treatments, while 1/4 dogs with grade IV recovered over 7 weeks after 15 treatments. Vomiting dogs with acute/subacute (n = 8) and chronic symptoms (n = 3) required about 1 and 7 treatments to recover fully, respectively. All dogs (n = 5) with abdominal pain showed fast relief within 24 hours after acupuncture. Two diarrhea cases recovered over 2–9 days after 1-2 treatments. Fifty-four of 66 coughing dogs were recovered by 1-2 treatments. And 5 of 6 epilepsy dogs under a regular acupuncture treatment had no epileptic episode during followup of 12 months. These results suggest that this flow chart can help the clinicians prescribe acupoints effectively.

Effect and mechanism of acupuncture on gastrointestinal diseases

Acupuncture modulates various biomechanical responses, such as prokinetic, antiemetic, and antinociceptive effects. Acupuncture treatment involves the insertion of thin needles into the skin and underlying muscle and the needles are stimulated manually or electrically. Thus, acupuncture stimulates the somatic afferent nerves of the skin and muscles. The somatic sensory information from the body is carried to the cortex area of the brain. Somatic sensory fibers also project to the various nuclei, including the brain stem, periaqueductal gray (PAG), and paraventricular nucleus (PVN) of the hypothalamus. Somatosensory pathways stimulated by acupuncture activate these nuclei. Activation of the brain stem modulates the imbalance between sympathetic activity and parasympathetic activity. Opioid released from the PAG is involved in mediating antiemetic and antinociceptive effects of acupuncture. Oxytocin release from the PVN mediates antistress and antinociceptive effects of acupuncture. Acupuncture may be effective in patients with functional gastrointestinal (GI) disorders because of its effects on GI motility and visceral pain. It is expected that acupuncture is used in the treatment of patients with functional GI disorders.

Effects and possible mechanisms of acupuncture at ST36 on upper and lower abdominal symptoms induced by rectal distension in healthy volunteers

Background acupuncture (AP) has been shown to have a therapeutic potential for gastrointestinal motility disorders. The aims of this study were to investigate the effects and possible mechanisms of acupuncture on postprandial upper and lower abdominal symptoms induced by rectal distension (RD). Twenty healthy volunteers were involved in a two-session study (AP and sham-AP, AP and no-AP, or sham-AP and no-AP). In 12 of the volunteers, RD was performed for 60 min in the postprandial state, and AP at ST36 or sham-AP was performed during the second 30-min period of RD. Gastric slow waves and heart rate variability (HRV) were recorded using the electrogastrogram and electrocardiogram, respectively. Upper and lower abdominal symptoms were scored during RD with AP and sham-AP. In five of the subjects, an additional experiment with two sessions (with AP and no-AP) was performed. In the remaining eight volunteers, the same experiment was performed with sham-AP and no-AP was performed. The results were, first, RD at an average volume of 171 ml induced upper and lower abdominal symptoms (P < 0.01). AP, but not sham-AP or no-AP, reduced both upper and lower abdominal symptoms (P < 0.05). Second, RD decreased the percentage of normal gastric slow waves (P < 0.05). AP improved gastric slow waves compared with sham-AP or no-AP (P < 0.05). Third, in the larger, but not smaller, sample size experiment, the vagal activity during the RD plus AP period was significantly higher than that during the RD alone period in the same session and the corresponding period with sham-AP or no-AP in other sessions (P < 0.05). Neither sham-AP nor no-AP showed any effects on vagal activity (P > 0.05). Finally, in the experiment with eight volunteers, neither sham-AP nor no-AP showed any effects on RD-induced impairment in gastric slow waves, abdominal symptoms, or vagal activity (P > 0.05). The conclusions are RD induces upper or lower abdominal symptoms and impairs gastric slow waves in healthy volunteers. AP at ST36 is able to improve upper and lower abdominal symptoms and impaired gastric slow waves induced by RD, possibly mediated via the vagal pathway.

Effects and mechanisms of electroacupuncture on glucagon-induced small intestinal hypomotility in dogs

BACKGROUND

Little is known on the effect of electroacupuncture (EA) (Br Med J, 2, 1976, 1225) on intestinal motility. The aim of this study was to investigate effects and mechanisms of EA on small intestinal contractions, transit, and slow waves in dogs.

METHODS

Six dogs were equipped with two intestinal cannulas for the measurement of small intestinal contractions and transit. Glucagon was used to induce postprandial intestinal hypomotility. Each dog was studied in five randomized sessions: Control, glucagon, glucagon + EA, glucagon + EA + naloxone, and glucagon + EA + atropine.

KEY RESULTS

1 In the fasting state, EA induced intestinal contractions during motor quiescence (contractile index or CI: 4.4 ± 0.8 VS 8.3 ± 0.7, P < 0.05). 2 In the fed state, EA improved glucagon-induced intestinal hypomotility (CI: 3.8 ± 0.4 VS 6.1 ± 0.6, P < 0.05). 3 Electroacupuncture accelerated intestinal transit delayed by glucagon (67.9 ± 4.3 VS 40.2 ± 5.0 min, P < 0.05). 4 There was a negative correlation between the CI and the total transit time (R(2) = 0.59, P < 0.05). 5 The excitatory effect of EA was blocked by naloxone and partially blocked by atropine. 6 The percentage of normal slow waves was reduced with glucagon (70 ± 2%VS 98 ± 1% at baseline, P = 0.0015). Electroacupuncture normalized impaired slow waves and the effect was blocked by naloxone.

CONCLUSIONS & INFERENCES

Electroacupuncture enhances intestinal contractions during Phase I of the migrating motor complex and glucagon-induced hypomotility in the fed state, and accelerates intestinal transit via the opioid and cholinergic pathways in dogs. Electroacupuncture may have a therapeutic potential for intestinal hypomotility.

Mechanism of acupuncture on neuromodulation in the gut--a review

INTRODUCTION

Acupuncture has been used for treating various gastrointestinal (GI) diseases. However, the mechanism of acupuncture remains unclear.

METHODS

The aim of this article is to review the published literature on the mechanism of acupuncture on neuromodulation in the gut.

RESULTS

Acupuncture treatment involves the insertion of thin needles into the skin and underlying muscle and the subsequent stimulation of the needles manually or electrically. Thus, acupuncture stimulates the somatic afferent nerves of the skin and muscles. The somatic sensory information from the body is carried to the cortex area of the brain. Somatic sensory fibers also project to the various nuclei at the brain stem and hypothalamus. Via somato-autonomic reflex, acupuncture modulates various biomechanical responses, such as prokinetic, antiemetic, and anti-nociceptive effects.

CONCLUSION

According to traditional Chinese medicine, "Acupuncture is believed to restore the balance of Yin and Yang." This can be translated into the Western medicine terminology that "Acupuncture modulates the imbalance between the parasympathetic and sympathetic activity." Acupuncture may be effective in patients with functional GI disorders because of its effects on GI motility and visceral pain.

Electroacupoint stimulation for postoperative nausea and vomiting in patients undergoing supratentorial craniotomy

OBJECTS

We evaluated the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) at the P6 acupoint for prevention of postoperative nausea and vomiting in patients undergoing supratentorial craniotomy.

METHODS

The study population was patients aged 20 to 60 years who underwent supratentorial craniotomy under general anesthesia. Exclusion criteria were obesity, diabetes mellitus, and a history of motion sickness, postoperative nausea and vomiting, or smoking. Patients were randomized into 2 groups: stimulation and control. In the former, transcutaneous stimulation electrodes were placed at the right P6 acupoint. In controls, electrodes were positioned at a nonacupoint site. Patients received a standard general anesthesia. Ondansetron was given as a routine antiemetic treatment for each patient before skin closure. Postoperatively, metoclopramide (10 mg, i.v.) was administered as a rescue antiemetic.

RESULT

Forty patients received TEAS and 40 were controls. In the TEAS group, 18% of patients had nausea compared with 37% of the controls. The cumulative prevalence of vomiting was 12.5% with acustimulation and 32.5% in controls (P<0.05). The prevalence of nausea, vomiting was significantly lower with TEAS at the P6 acupoint.

CONCLUSIONS

TEAS at the P6 meridian points is an effective adjunct to standard antiemetic drug therapy for prevention of nausea and vomiting in patients undergoing supratentorial craniotomy.

Electroacupuncture improves impaired gastric motility and slow waves induced by rectal distension in dogs

Rectal distension (RD) is known to induce upper gastrointestinal (GI) symptoms. The aim of this study was to investigate the effects and underlying mechanisms of RD on gastric slow waves (GSW) and motor activity and furthermore to investigate the effects and mechanisms of electroacupuncture (EA) on GSW and motor activity. Eight female hound dogs chronically implanted with gastric serosal electrodes and a gastric fistula were studied in six separate sessions. Antral motility, GSW, heart rate variability, and rectal pressure were evaluated for the above purposes. 1) RD at a volume of 120 ml suppressed antral motility significantly. Guanethidine blocked the inhibitory effect of RD. EA at ST36 was able to restore the suppressed antral contractions induced by RD (16.6+/-1.7 vs. 8.0+/-1.4, P<0.001). Naloxone partially blocked the effect of EA on antral contractions. 2) RD reduced the percentage of normal GSW from 98.8+/-0.8% at baseline to 76.1+/-8.6% (P<0.05) that was increased to 91.8+/-3.0% with EA. The effects of EA on the GSW were nullified by the presence of naloxone. 3) EA did not show any significant effect on rectal pressure, suggesting that the ameliorating effects of EA on RD-induced impaired gastric motility were not due to a decrease in rectal pressure. 4) EA increased the vagal activity suppressed by RD. In conclusion, RD inhibits postprandial gastric motility and impairs GSW in dogs, and the inhibitory effects are mediated via the adrenergic pathways. EA at ST36 is able to restore the RD-induced impaired GSW and motor activities, possibly by enhancing vagal activity, and is partially mediated via the opioid pathway. EA may have therapeutic potential for functional gastrointestinal disorders.

Holistic Acupuncture approach to idiopathic refractory nausea, abdominal pain and bloating

AIM: To evaluate the effectiveness of a holistic acupuncture approach on nausea, pain, bloating and electrogastrogram (EGG) parameters in patients with intractable symptoms.

METHODS: Twelve patients with no or mild nausea (those without nausea had bloating or pain) and 10 with a history of moderate to severe nausea were referred for acupuncture. All underwent an EGG and were treated at acupuncture points PC6, SP4 and DU20. Visual analog scales (VAS) assessing severity of nausea, pain and bloating were obtained before and after acupuncture treatment. Nineteen patients received three and three patients received two treatments.

RESULTS: VAS scores for nausea reflected the clinical assessment and differed significantly between mild and moderate/severe nausea groups. Acupuncture significantly improved severity of nausea in both groups with improved pre-treatment nausea between the first and third treatments in the moderate/severe nausea group. Pain scores improved with acupuncture in the mild nausea group only and bloating improved only with the first treatment in this group. Patients with bloating with VAS scores greater than 35 pre-treatment improved with acupuncture and over all VAS scores for pain improved with treatment. Acupuncture increased the power in the 2.7 to 3.5 cpm range in the EGG.

CONCLUSION: In this uncontrolled clinical study, a holistic acupuncture approach significantly improved nausea in patients with refractory symptoms and increased the power in the 2.7-3.5 cpm component of the electrogastrogram. Bloating and pain VAS scores improved acutely with treatment. This study suggests that acupuncture may be effective in this refractory group of patients and further study using appropriate controls is warranted.

Central effects of morphine on GI motility in conscious dogs

It has been suggested that morphine has dual effects; emetic effects and anti-emetic effects. The chemoreceptor trigger zone, which is outside the BBB, mediates the emetic effect. In contrast, the vomiting center mediates the anti-emetic effect of opioids. Thus, naloxone methiodide, which does not cross the BBB, antagonizes emetic effects of opioids. We studied whether naloxone methiodide alters abnormal motility pattern induced by morphine in gastrointestinal (GI) tract. Strain gauge force transducers were sutured on the serosal surface of upper GI tract to record the circular muscle contractions in eight dogs. The ventricular access system was implanted to inject morphine intracerebroventricularly (icv). Effects of icv-injection of morphine (0.3-3.0 mug/kg, bolus) on GI motility were studied during intravenous infusion of naloxone hydrochloride or naloxone methiodide. Icv-injection of morphine (3.0 mug/kg) induced retching and vomiting in all dogs tested. Phasic contractions of the jejunum were observed after icv-injection of morphine. These contractions in the jejunum migrated orally to the antrum (retrograde peristaltic contractions; RPCs). Both naloxone hydrochloride and naloxone methiodide treatment virtually abolished the emetic effects of morphine. Naloxone hydrochloride completely abolished morphine-induced RPCs in all dogs, whereas naloxone methiodide converted morphine-induced RPCs to anterograde peristaltic contractions (APCs) in 6 of 8 dogs. Our current study suggests that central opioids may induce APCs and prevent emesis in conscious dogs. Naloxone methiodide may be useful to prevent the undesired side effects of morphine.

Dual pulse intestinal electrical stimulation normalizes intestinal dysrhythmia and improves symptoms induced by vasopressin in fed state in dogs

To assess effects of dual pulse intestinal electrical stimulation (DPIES) on intestinal dysrhythmia and motility, and symptoms induced by vasopressin in conscious dogs. The study was performed in three postprandial sessions (control; vasopressin; DPIES) in six dogs with two pairs of electrodes chronically implanted on the serosal surface of the proximal jejunum and with a chronic duodenal fistula. A manometric catheter was advanced into the small intestine via the intestinal cannula. Motility and intestinal slow waves were recorded. Symptoms were assessed. During vasopressin infusion, the percentage of normal intestinal slow wave frequency was decreased (P < 0.01), reflected as a significant increase in the percentage of both bradygastria and tachygastria; the motility index decreased (P < 0.01) and the symptom score increased (P < 0.01). In the session of DPIES, the percentage of normal slow wave frequency was recovered (P < 0.05 vs vasopressin), attributed to a reduction in both bradyarrhythmia and tachyarrhythmia; the symptom score was reduced (P < 0.05 vs vasopressin); the motility index was not significantly increased. These results suggest that vasopressin induces intestinal dysrhythmia and emetic symptoms and inhibits intestinal motility. Dual pulse intestinal electrical stimulation is capable of improving intestinal dysrhythmia and emetic symptoms but not impaired intestinal motility induced by vasopressin.

Researching complementary and alternative treatments--the gatekeepers are not at home

Background

To explore the strengths and weaknesses of conventional biomedical research strategies and methods as applied to complementary and alternative medicine (CAM), and to suggest a new research framework for assessing these treatment modalities.

Discussion

There appears to be a gap between published studies showing little or no efficacy of CAM, and reports of substantial clinical benefit from patients and CAM practitioners. This "gap" might be partially due to the current focus on placebo-controlled randomized trials, which are appropriately designed to answer questions about the efficacy and safety of pharmaceutical agents. In an attempt to fit this assessment strategy, complex CAM treatment approaches have been dissected into standardized and often simplified treatment methods, and outcomes have been limited.

Unlike conventional medicine, CAM has no regulatory or financial gatekeeper controlling their therapeutic "agents" before they are marketed. Treatments may thus be in widespread use before researchers know of their existence. In addition, the treatments are often provided as an integrated 'whole system' of care, without careful consideration of the safety issue.

We propose a five-phase strategy for assessing CAM built on the acknowledgement of the inherent, unique aspects of CAM treatments and their regulatory status in most Western countries. These phases comprise:

1. Context, paradigms, philosophical understanding and utilization

2. Safety status

3. Comparative effectiveness.

4. Component efficacy

5. Biological mechanisms.

Summary

Using the proposed strategy will generate evidence relevant to clinical practice, while acknowledging the absence of regulatory and financial gatekeepers for CAM. It will also emphasize the important but subtle differences between CAM and conventional medical practice.

Endogenous opiates and behavior: 2005

This paper is the 28th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2005 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity, neurophysiology and transmitter release (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); immunological responses (Section 17).

Acupuncture for nausea and vomiting: An update of clinical and experimental studies

The objective of this overview is to summarize existing knowledge about the effects of acupuncture-point stimulation on nausea and vomiting. Systematic reviews on postoperative nausea and vomiting, chemotherapy-induced nausea and vomiting, and pregnancy-related nausea and vomiting exist. Several randomised trials, but no reviews, exist for motion sickness. For postoperative nausea and vomiting, results from 26 trials showed acupuncture-point stimulation was effective for both nausea and vomiting. For chemotherapy-induced nausea and vomiting, results of 11 trials differed according to modality with acupressure appearing effective for first-day nausea, electroacupuncture appearing effective for first-day vomiting, and noninvasive electrostimulation appearing no more effective than placebo for any outcome. For pregnancy-related nausea and vomiting, results were mixed. Experimental studies showed effects of P6-stimulation on gastric myoelectrical activity, vagal modulation and cerebellar vestibular activities in functional magnetic resonance imaging. There is good clinical evidence from more than 40 randomised controlled trials that acupuncture has some effect in preventing or attenuating nausea and vomiting. A growing number of experimental studies suggest mechanisms of action.

How do acupuncture and moxibustion act? - Focusing on the progress in Japanese acupuncture research -

The mechanisms of action of acupuncture and moxibustion as reported by Japanese researchers are reviewed. The endogenous opioid-mediated mechanisms of electroacupuncture (EA) as used in China are well understood, but these are only one component of all mechanisms of acupuncture. These studies emphasize the similarity of the analgesic action of EA to various sensory inputs to the pain inhibition mechanisms. In Japanese acupuncture therapy, careful detection of the acupuncture points and fine needling technique with comfortable subjective sensation are considered important. The role of polymodal receptors (PMR) has been stressed based on the facts that PMRs are responsive to both acupuncture and moxibustion stimuli, thermal sensitivity is essential in moxibustion therapy, and the characteristics of acupuncture points and trigger points are similar to those of sensitized PMRs. Acupuncture and moxibustion are also known to affect neurons in the brain reward systems and blood flow in skin, muscle, and nerve. Axon reflexes mediated by PMRs might be a possible mechanism for the immediate action of acupuncture and moxibustion. Reports on the curative effects of acupuncture on various digestive and urological disorders are also reviewed briefly.

Acupuncture for functional gastrointestinal disorders

Functional gastrointestinal (GI) symptoms are common in the general population. Especially, motor dysfunction of the GI tract and visceral hypersensitivity are important. Acupuncture has been used to treat GI symptoms in China for thousands of years. It is conceivable that acupuncture may be effective in patients with functional GI disorders because it has been shown to alter acid secretion, GI motility, and visceral pain. Acupuncture at the lower limbs (ST-36) causes muscle contractions via the somatoparasympathetic pathway, while at the upper abdomen (CV-12) it causes muscle relaxation via the somatosympathetic pathway. In some patients with gastroesophageal reflux disease (GERD) and functional dyspepsia (FD), peristalsis and gastric motility are impaired. The stimulatory effects of acupuncture at ST-36 on GI motility may be beneficial to patients with GERD or FD, as well as to those with constipation-predominant irritable bowel syndrome (IBS), who show delayed colonic transit. In contrast, the inhibitory effects of acupuncture at CV-12 on GI motility may be beneficial to patients with diarrhea-predominant IBS, because enhanced colonic motility and accelerated colonic transit are reported in such patients. Acupuncture at CV-12 may inhibit gastric acid secretion via the somatosympathetic pathway. Thus, acupuncture may be beneficial to GERD patients. The antiemetic effects of acupuncture at PC-6 (wrist) may be beneficial to patients with FD, whereas the antinociceptive effects of acupuncture at PC-6 and ST-36 may be beneficial to patients with visceral hypersensitivity. In the future, it is expected that acupuncture will be used in the treatment of patients with functional GI disorders.

Electroacupuncture at ST-36 accelerates colonic motility and transit in freely moving conscious rats

Acupuncture is useful for functional bowel diseases, such as constipation and diarrhea. However, the mechanisms of beneficial effects of acupuncture on colonic function have scarcely ever been investigated. We tested the hypothesis that electroacupuncture (EA) at ST-36 stimulates colonic motility and transit via a parasympathetic pathway in conscious rats. Hook-shaped needles were inserted at bilateral ST-36 (lower limb) or BL-21 (back) and electrically stimulated at 10 Hz for 20 min. We also studied c-Fos expression in response to EA at ST-36 in Barrington's nucleus of the pons. EA at ST-36, but not BL-21, significantly increased the amplitude of motility at the distal colon. The calculated motility index of the distal colon increased to 132 +/- 9.9% of basal levels (n = 14, P < 0.05). In contrast, EA at ST-36 had no stimulatory effects in the proximal colon. EA at ST-36 significantly accelerated colonic transit [geometric center (GC) = 6.76 +/- 0.42, n = 9, P < 0.001] compared with EA at BL-21 (GC = 5.23 +/- 0.39, n = 7). The stimulatory effect of EA at ST-36 on colonic motility and transit was abolished by pretreatment with atropine. EA-induced acceleration of colonic transit was also abolished by extrinsic nerve denervation of the distal colon (GC = 4.69 +/- 0.33, n = 6). The number of c-Fos-immunopositive cells at Barrington's nucleus significantly increased in response to EA at ST-36 to 8.1 +/- 1.1 cells/section compared with that of controls (2.4 +/- 0.5 cells/section, n = 3, P < 0.01). It is concluded that EA at ST-36 stimulates distal colonic motility and accelerates colonic transit via a sacral parasympathetic efferent pathway (pelvic nerve). Barrington's nucleus plays an important role in mediating EA-induced distal colonic motility in conscious rats.