The effect of acupuncture on blood pressure: the interrelation of sympathetic activity and endogenous opioid peptides

Recent Research Trends in Moxibustion Treatment in Korea

A total of 1,235 studies were retrieved on June 23, 2019, from 3 databases. Selected 59 studies were evaluated by year of publication, study type, subject condition/disease, acupoint, standards for reporting interventions in clinical trials of moxibustion (STRICTOM), Cochrane risk of bias (RoB), and risk of bias assessment tool for non-randomized study (RoBANS). Most studies were conducted in 2011, after which the number of studies decreased. The most common study type was 25 case reports (CR), 16 uncontrolled clinical trials (UCT), 11 randomized controlled trials (RCT), and 7 controlled clinical trials (CCT). Moxibustion treatment was mainly used for musculoskeletal and circulatory diseases/conditions. A total of 83 acupoints were used, A-shi points being the most used. As for STRICTOM, an average of 7.4 items were satisfactory for UCT and CR without a control group, and an average of 9.4 items were satisfactory for RCT and CCT. RCT was assessed using the RoB, and many items were rated as uncertain. In this study, the need for RCT of moxibustion treatment in Korea was identified. The detailed description of study methods and results will provide evidence for the efficacy of moxibustion treatment in preventive and therapeutic aspects of Korean traditional medicine.

Acupuncture in the Treatment of Hypertension and Stroke

This article identifies and comments on published studies of acupuncture treatment for hypertension and stroke. In all, 27 appropriate papers were analysed: 13 were hypertension papers with 3 being of controlled trials, and 14 were stroke papers with 5 controlled trials. The articles consisted of randomised controlled trials (RCTs), controlled trials, and case series studies. The hypertension papers also involved some cohort studies. In general, sample sizes of these studies were small.

Acupuncture in these papers was used as a secondary intervention for treating hypertension and as a tertiary intervention for stroke rehabilitation. The RCTs (the top of the hierarchy of evidence) of hypertension showed that acupuncture was not more effective than sham acupuncture or the anti-hypertensive drug, reserpine; however, all the case series suggested that acupuncture was an effective treatment. The RCT evidence for stroke showed that the effectiveness of acupuncture was similar to that of conventional treatment. The conclusion was that from the papers analysed there is insufficient evidence to show that acupuncture produces better results than other treatments for hypertension or stroke.

Proteomic response to acupuncture treatment in spontaneously hypertensive rats

Previous animal and clinical studies have shown that acupuncture is an effective alternative treatment in the management of hypertension, but the mechanism is unclear. This study investigated the proteomic response in the nervous system to treatment at the Taichong (LR3) acupoint in spontaneously hypertensive rats (SHRs). Unanesthetized rats were subject to 5-min daily acupuncture treatment for 7 days. Blood pressure was monitored over 7 days. After euthanasia on the 7^th day, rat medullas were dissected, homogenized, and subject to 2D gel electrophoresis and MALDI-TOF analysis. The results indicate that blood pressure stabilized after the 5th day of acupuncture, and compared with non-acupoint treatment, Taichong-acupunctured rat’s systolic pressure was reduced significantly (P<0.01), though not enough to bring blood pressure down to normal levels. The different treatment groups also showed differential protein expression: the 2D images revealed 571±15 proteins in normal SD rats’ medulla, 576±31 proteins in SHR’s medulla, 597±44 proteins in medulla of SHR after acupuncturing Taichong, and 616±18 proteins in medulla of SHR after acupuncturing non-acupoint. In the medulla of Taichong group, compared with non-acupoint group, seven proteins were down-regulated: heat shock protein-90, synapsin-1, pyruvate kinase isozyme, NAD-dependent deacetylase sirtuin-2, protein kinase C inhibitor protein 1, ubiquitin hydrolase isozyme L1, and myelin basic protein. Six proteins were up-regulated: glutamate dehydrogenase 1, aldehyde dehydrogenase 2, glutathione S-transferase M5, Rho GDP dissociation inhibitor 1, DJ-1 protein and superoxide dismutase. The altered expression of several proteins by acupuncture has been confirmed by ELISA, Western blot and qRT-PCR assays. The results indicate an increase in antioxidant enzymes in the medulla of the SHRs subject to acupuncture, which may provide partial explanation for the antihypertensive effect of acupuncture. Further studies are warranted to investigate the role of oxidative stress modulation by acupuncture in the treatment of hypertension.

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.

Electroacupuncture improves rectal distension-induced delay in solid gastric emptying in dogs

The aim of this study was to investigate the effects and mechanisms of electroacupuncture (EA) on rectal distension (RD)-induced delay in solid gastric emptying in dogs. Gastric emptying of solids was assessed in 12 dogs chronically implanted with a duodenal cannula by collecting samples at different time points from the cannula and measuring the dried weights of the samples. Bethanechol and atropine were used to qualitatively validate the method. In separate experiments, gastric emptying of solids was measured in a number of sessions: control, RD, RD + sham-EA, RD + EA of 6 mA, RD + EA of 3 mA, and RD + EA + naloxone. The method of gastric emptying by collecting and drying gastric chyme from the duodenal cannula was found to be accurate and reliable. Using the method, we found gastric emptying to be accelerated with bethanechol (70.01 ± 8.10% vs. 82.61 ± 4.15%, P = 0.04, vs. control) and delayed with atropine (4.31 ± 1.57%, P < 0.001, vs. control). RD substantially and significantly delayed gastric emptying. EA, but not sham-EA, attenuated delayed gastric emptying induced by RD (sham-EA: 48.79 ± 9.47% vs. EA: 74.28 ± 5.96%, P < 0.01). The effect was more potent with EA of 6 mA than EA of 3 mA and blocked by naloxone. EA is able to attenuate RD-induced delay in gastric emptying of solids, and this ameliorating effect may be mediated via the opioid pathway. EA may have a therapeutic potential for treating delayed gastric emptying attributed to lower gut distension.

Pulse width modulation electro-acupuncture on cardiovascular remodeling and plasma nitric oxide in spontaneously hypertensive rats

This study was designed to investigate the effect of pulse width modulation electro-acupuncture (PWM-EA) on cardiovascular remodeling and nitric oxide (NO) in spontaneously hypertensive rats (SHR). Thirty-four male SHR were randomly divided into control, captopril, and two PWM-EA groups, which were treated with 350 Hz (SHR-350 Hz) and whole audio bandwith electro-acupuncture (SHR-WAB group) respectively, on the ST 36 point located on the outside of the hind leg. Systolic blood pressure (BP), plasma and myocardial NO were measured. Histological studies were also performed on the aortic wall and the left ventricle. The BP in the SHR-350 Hz, SHR-WAB and the captopril groups was lower than in the control group following the treatment (P < .05). The average aortic media wall thickness in the two electro-acupuncture groups was less than in the control group (P < .05). The left ventricle/heart weight ratio in the captopril and SHR-350 Hz groups was less than in the control group (P < .01), but was similar between the SHR-WAB and the control group (P > .05). The plasma and myocardium NO levels were elevated in the captopril and the SHR-350 Hz group (P < .05 and .01, resp.). The plasma level of NO in the SHR-WAB group was also higher than in the control group (P < .05). We concluded that pulse width modulation electro-acupuncture on the ST 36 point prevents the progression of hypertension and diminishes the cardiovascular remodeling in SHR. It also elevates plasma and cardiac NO in this animal model.

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.

Prehospital analgesia with acupressure at the Baihui and Hegu points in patients with radial fractures: a prospective, randomized, double-blind trial

BACKGROUND

Pain during transportation is a common phenomenon in emergency medicine. As acupressure has been deemed effective for pain management by the National Institutes of Health, we conducted a study to evaluate its effectiveness in prehospital patients with isolated distal radial fracture.

METHODS

This was a prospective, randomized, double-blind study. Thirty-two patients were enrolled. Acupressure was performed either at "true" points or at "sham" points. Vital signs and pain and anxiety scores were recorded before and after the acupressure treatment. Normally distributed values were compared using the Student t test.

RESULTS

Pretreatment scores for pain and anxiety were similar in the 2 groups (47.6 +/- 8.9 vs 51.2 +/- 8.7 visual analog scale [VAS] score for pain, 52.4 +/- 6.0 vs 47.5 +/- 9.3 VAS score for anxiety). At the hospital, patients in the true-points group had significantly lower pain (36.6 +/- 11.0 vs 56.0 +/- 13.3 VAS score, P < .001) and anxiety scores (34.9 +/- 22.2 vs 53.4 +/- 19.7 VAS score, P = .022).

CONCLUSION

Acupressure in the prehospital setting effectively reduces pain and anxiety in patients with distal radial trauma.

Short-term electroacupuncture at Zusanli resets the arterial baroreflex neural arc toward lower sympathetic nerve activity

Although electroacupuncture reduces sympathetic nerve activity (SNA) and arterial pressure (AP), the effects of electroacupuncture on the arterial baroreflex remain to be systematically analyzed. We investigated the effects of electroacupuncture of Zusanli on the arterial baroreflex using an equilibrium diagram comprised of neural and peripheral arcs. In anesthetized, vagotomized, and aortic-denervated rabbits, we isolated carotid sinuses and changed intra-carotid sinus pressure (CSP) from 40 to 160 mmHg in increments of 20 mmHg/min while recording cardiac SNA and AP. Electroacupuncture of Zusanli was applied with a pulse duration of 5 ms and a frequency of 1 Hz. An electric current 10 times the minimal threshold current required for visible muscle twitches was used and was determined to be 4.8 +/- 0.3 mA. Electroacupuncture for 8 min decreased SNA and AP (n = 6). It shifted the neural arc (i.e., CSP-SNA relationship) to lower SNA but did not affect the peripheral arc (i.e., SNA-AP relationship) (n = 8). SNA and AP at the closed-loop operating point, determined by the intersection of the neural and peripheral arcs, decreased from 100 +/- 4 to 80 +/- 9 arbitrary units and from 108 +/- 9 to 99 +/- 8 mmHg (each P < 0.005), respectively. Peroneal denervation eliminated the shift of neural arc by electroacupuncture (n = 6). Decreasing the pulse duration to <2.5 ms eliminated the effects of SNA and AP reduction. In conclusion, short-term electroacupuncture resets the neural arc to lower SNA, which moves the operating point toward lower AP and SNA under baroreflex closed-loop conditions.

The Anti-Inflammatory Effects of Low- and High-Frequency Electroacupuncture Are Mediated by Peripheral Opioids in a Mouse Air Pouch Inflammation Model

BACKGROUND

Although acupuncture has been widely used for complementary therapeutic approaches to treat inflammatory diseases and inflammation-induced pain, the potential anti-inflammatory effects of acupuncture treatment remain controversial in clinical trials, and the underlying mechanisms are still unclear.

OBJECTIVE

The objective was to determine whether electroacupuncture (EA) is able to suppress the peripheral inflammatory response (e.g., zymosan-induced leukocyte migration into air pouch). As part of a mechanistic approach, it was further evaluated whether endogenous opioid systems are involved in the "EA-induced anti-inflammatory effect" (EA-AI).

METHODS

EA (1 or 120 Hz) was performed bilaterally in the Zusanli acupoint (ST36) or in a nonacupoint (gluteal muscle) for 30 min in ICR mice under anesthetic condition. The number of leukocytes that migrated into the air pouch was counted 4 hours after zymosan injection. EA was performed at 0, 0.5, 1, or 2 hours prior to zymosan injection, respectively. To evaluate opioid involvement in EA-AI, intrathecal naloxone (36 microg/mouse) and intraperitoneal naloxone methiodide (30 mg/kg) were administered 10 min before EA stimulation.

RESULTS

Both the 1 and 120 Hz frequencies of EA into Zusanli acupoint at the same time with zymosan injection significantly reduced leukocyte migration into the air pouch as compared with those of control groups (i.e., anesthetic control and needling control into Zusanli acupoint without electrical stimulation). The EA stimulation into nonacupoint did not produce any significant anti-inflammatory effect. EA treatment at 0.5 hours prior to zymosan injection also produced an anti-inflammatory effect but 1 and 2 hours prior to zymosan injection did not elicit any effect. Peripheral opioid blockage significantly reversed EA-AI, whereas spinal opioid blockage did not alter EA-AI.

CONCLUSION

EA can suppress peripheral inflammation through a peripheral opioid mechanism. To achieve the full effectiveness of EA, repeated application is recommended for the treatment of a variety of inflammatory diseases.

Electroacupuncture reduces rectal distension-induced blood pressure changes in conscious dogs

It has been shown that acupuncture relieves symptoms of abdominal pain and bloating in patients with irritable bowel syndrome (IBS). However, the mechanism of beneficial effects of acupuncture still remains unproven. The aim of the present study was to investigate the mechanisms of the antinociceptive effects of acupuncture in conscious dogs. We evaluated the increase in mean arterial blood pressure (MAP) caused by rectal distension as an index of visceral pain. Electroacupuncture (EA; 10 Hz) at ST-36 (lower leg), but not at BL-21 (back), significantly reduced the increase in MAP in response to rectal distension (30 and 40 cm3). The antinociceptive effect of EA at ST-36 was abolished by pretreatment with naloxone (a central and peripheral opioid receptor antagonist) but not by naloxone methiodide (a peripheral opioid receptor antagonist). These results suggest that EA at ST-36 may reduce visceral pain via central opioid pathway. Acupuncture may be useful to treat visceral hypersensitivity in IBS patients.

Is there a vasospasmolytic effect of acupuncture in patients with secondary Raynaud phenomenon? Gibt es einen vasospasmolytischen Effekt der Akupunktur bei Patienten mit sekundarem Raynaud-Phanomen?

BACKGROUND

Raynaud phenomenon (RP) is a vasospastic disorder of the digital arteries. Severe forms are found in patients with connective tissue diseases. Vasospasmolytic therapies are often limited by side effects such as orthostatic hypotension.

PATIENTS/METHODS

We investigated therefore the effect of acupuncture in a double blind, placebo-controlled, randomized trial in patients with secondary RP. The study was performed during the winter season by licensed acupuncturists weekly for 8 weeks (points chosen for the verum group: L.I.4, S.J.5, St.36, P.6, Du.20, Ex.28).

RESULTS

An improvement was detected in both groups but there was no significant effect on clinical symptoms - based on patient diaries (average number of attacks before and after treatment: verum 1.9 +/- 2.0 vs. 1.4 +/- 1.7 attacks/ day and placebo 2.8 +/- 1.8 vs. 1.9 +/- 1.1; duration of attacks: verum 15 +/- 12 vs. 12 +/- 9 min. and placebo 31 +/- 17 vs. 16 +/- 6; n.s.) or on skin microcirculation, measured by local cold testing.

CONCLUSIONS

A specific vasospasmolytic effect of acupuncture could not be proven. This may be due to minor morphologic changes of supplying arteries or a severe local defect in endothelial function rather than a neurological disturbance which might be influenced by acupuncture. Much larger studies would be needed to identify the possible small benefit from acupuncture. If long-term relief is not obtained, it is unlikely to be cost-effective.

Stop Hypertension with the Acupuncture Research Program (SHARP): clinical trial design and screening results

Hypertension is a major public health problem with serious medical and financial consequences. Barriers to successful conventional pharmacological treatment include side effects, out-of-pocket expenses, patient noncompliance and insufficient dosages. Acupuncture has been studied as an alternative therapy for controlling blood pressure (BP) but previous studies have serious methodological limitations. This paper describes the design of the Stop Hypertension with the Acupuncture Research Program (SHARP) trial, a pilot randomized clinical trial designed to gather preliminary data regarding the efficacy of traditional Chinese medicine (TCM)-based acupuncture for control of essential hypertension. The design of the SHARP trial balanced rigorous clinical trial methodology with principles of TCM. Eligible participants had systolic BP (SBP) 140-179 mm Hg and diastolic BP (DBP) 90-109 mm Hg in the absence of antihypertensive therapy. Following screening, participants were randomized to one of three groups: individualized, standardized or control acupuncture. Treatments were designed according to principles of TCM; nonspecific effects associated with the interventions were standardized across the randomized groups. For individualized acupuncture, points were tailored to each participant. Standardized acupuncture used a prespecified set of points. The invasive sham control acupuncture regimen was designed to be non-active. Each participant received a "prescription" for individualized acupuncture from an acupuncturist who was masked to treatment assignment, and was subsequently treated by an independent acupuncturist. Patients and those assessing BP were masked to treatment group. Acupuncture was delivered twice a week for 6 weeks. Follow-up visits were every 2 weeks to week 10 and then at months 4, 6, 9 and 12. The primary endpoint will be change in SBP from baseline to 10 weeks. DBP, BP trajectories over the 12-month follow-up and antihypertensive medication requirements will also be examined. Initial contact was documented for 1442 prospective participants from March 2001 to April 2002; 424 provided informed consent and 192 were ultimately randomized.

Effect of electroacupuncture on minimum alveolar concentration of isoflurane in dogs

The effect of electroacupuncture (EA) on minimum alveolar concentration (MAC) of isoflurane was evaluated in dogs. After determination of baseline MAC, EA was applied at each acupoints (LI-4, SP-6, ST-36 and TH-8) and nonacupoint for 30 min. MAC was determined again. EA at acupoints significantly lowered the MAC of isoflurane in dogs (17.5 +/- 3.1%, 21.3 +/- 8.0%, 21.2 +/- 7.5% and 15.4 +/- 3.1%, respectively). In control group and nonacupoint electrical stimulation group MAC were not decreased significantly. From these results, electroacupuncture at each acupoints used in the present study would have an advantage in isoflurane anesthesia with reducing its requirement.

Selected complementary methods and nursing care of the hypertensive client

The National Institutes of Health and the World Health Organization have targeted the treatment of mild or borderline hypertension as a critical health care issue. Conventional practitioners' focus on more intensive treatment for blood pressure elevations in the lower ranges is accompanying the consumer-driven movement toward the use of complementary methods. Over 60 million Americans used herbal therapies in the past year, and visits to complementary care practitioners are expected to increase beyond the 425 million now made annually. The purpose of this article is to identify four herbs that consumers commonly select for the treatment of hypertension and identify nursing care considerations for their use. Additionally, the article reviews research on the effectiveness of acupuncture for hypertension, along with nursing care implications for patients.

Rostral ventrolateral medullary opioid receptor subtypes in the inhibitory effect of electroacupuncture on reflex autonomic response in cats

Electroacupuncture (EA) is used in traditional Chinese medicine to treat arrhythmias, hypertension and myocardial ischemia. Our previous work suggests that the inhibitory effect of EA on the pressor reflex induced by bradykinin (BK) applied to the gallbladder is due, in part, to the activation of opioid receptors, most likely located in the rostral ventrolateral medulla (rVLM). However, specific opioid receptor subtypes, and hence the neurotransmitters. responsible for this inhibition are unknown. Therefore, in anesthetized cats, BK (10 microg/ml) was applied to the gallbladder to induce transient reflex increases in arterial blood pressure (BP). EA (1-2 mA, 5 Hz, 0.5 ms pulses) was delivered through acupuncture needles inserted bilaterally into Neiguan and Jianshi acupoints on forelimbs, overlying the median nerves. EA attenuated the BK-induced pressor response by 39%. Opioid receptor subtype antagonists or agonists were microinjected unilaterally into the rVLM. The mu- and delta-receptor antagonists CTOP and ICI 174,864, respectively, significantly attenuated the EA-induced inhibition for at least 30 min. The K-receptor antagonist (nor-BNI) was less effective and was shorter acting. Like EA, microinjection of mu- and delta-opioid agonists, DAGO and DADLE, respectively, into the rVLM significantly decreased the pressor responses. In contrast, the kappa-opioid agonist, U50,488, failed to alter the BK-induced pressor response. We conclude that a significant portion of inhibition of the gallbladder pressor response by EA is related to activation of mu- and delta-opioid receptors in the rVLM. The endogenous neurotransmitters for mu- and delta-opioid receptors, beta-endorphins and enkephalins, in the rVLM, therefore appear to play a role in the EA-related modulation of cardiovascular reflex responses. Conversely, dynorphin is less likely to be involved in this response.

Influence of acupuncture on Doppler ultrasound in pregnant women

OBJECTIVE

To evaluate the influence of acupuncture on the blood flow in the umbilical artery (UA), fetal aorta and uterine artery and on the fetal heart rate using two different acupuncture points (SP-6 (Sanyinjiao) and LI-4 (Hegu)).

METHODS

In group A (n = 50), measurements (Doppler ultrasound and fetal heart rate) were performed at term after an uneventful pregnancy (#1) followed by acupuncture treatment using the acupuncture-point SP-6 bilaterally. The treatment time lasted 15 min after which the next measurement (#2) was carried out. The needles were then inserted into the LI-4 acupuncture point for a further 15 min. A third measurement at the end of acupuncture treatment (#3) completed the session. In group B (n = 25), measurements were made before (#1) and after (#4) acupuncture at LI-4 acupuncture points only.

RESULTS

In group A, the mean systolic/diastolic (S/D) ratios of UA #1, UA #2 and UA #3 were 2.45, 2.38 and 2.22, respectively (P = 0.0012). The difference in mean S/D ratios between UA #1 and UA #3 as well as that between UA #2 and UA#3 were statistically significant (P = 0.0002 and P = 0.008, respectively). There was no difference between the mean S/D ratios of the uterine artery and between the mean resistance indices of the fetal aorta. In group B, the only significant difference between measurements following acupuncture treatment was in fetal heart rate (139 vs. 143 bpm, P = 0.02).

CONCLUSION

Our study indicates a positive influence of acupuncture treatment on umbilical artery waveforms when using a combination of SP-6 (Sanyinjiao) and LI-4 (Hegu) acupuncture points. Acupuncture performed at these sites either individually or in combination does not seem to affect blood flow in the fetal aorta or uterine artery.

Cardiovascular and endocrine effects of acupuncture in hypertensive patients

It has been reported that acupuncture can decrease blood pressure in patients with hypertension, possibly by an endocrine mechanism. The aim of the present study was to investigate the effects of acupuncture on arterial blood pressure and the secretion of renin, vasopressin and cortisol in hypertensive patients. Acupuncture was performed in fifty untreated essential hypertensive patients resting in the supine position. Thirty min after acupuncture there were decreases in systolic pressure from 169 +/- 2 to 151 +/- 2 mm Hg, diastolic pressure from 107 +/- 1 to 96 +/- 1 mm Hg, and heart rate from 77 +/- 2 to 72 +/- 2 bpm (P < 0.01). Plasma renin activity decreased from 1.7 +/- 0.4 to 1.1 +/- 0.2 ng/ml/2h (P < 0.01), but there were no significant changes in plasma vasopressin or cortisol concentrations. These results confirm that acupuncture decreases blood pressure in hypertensive patients, and suggest that the decrease results, at least in part, from a decrease in renin secretion.

Neural mechanism of depressor responses of arterial pressure elicited by acupuncture-like stimulation to a hindlimb in anesthetized rats

The effects of acupuncture-like stimulation of a hindlimb on renal sympathetic nerve activity (RNA) as well as mean arterial blood pressure (MAP) were examined in anesthetized rats. An acupuncture needle (diameter of 160 microns) was inserted into the skin of a hindlimb and underlying muscles to a depth of 5 mm and was twisted at about 1 Hz. Under deep anesthetic condition, in about 70% of trials, acupuncture-like stimulation for 60 s induced a decrease in MAP which was accompanied by a decrease in RNA. Acupuncture-like stimulation applied to the muscles alone, but not to the skin alone, induced inhibition of RNA and MAP. Transection of sciatic and femoral nerves ipsilateral to the hindlimb stimulation completely abolished the responses of RNA and MAP. The hindlimb stimulation excited the femoral and common peroneal afferent nerves. In spinalized animals, the hindlimb stimulation did not produce any changes in RNA and MAP. The results indicate that the decrease in MAP induced by acupuncture-like stimulation of a hindlimb is a reflex response. The afferent pathway is composed of hindlimb muscle afferents while the efferent pathway is composed of sympathetic vasoconstrictors including the renal nerves. Endogenous opioids may not be involved in the present reflex, because an intravenous injection of naloxone, an antagonist of the opioid receptors, did not influence the reflex.

Low-frequency transcutaneous nerve stimulation in mild/moderate hypertension

Low-frequency peripheral nerve stimulation may induce widespread cutaneous and muscular vasodilatation in animals and humans due to sympatho-inhibition. This response has in humans been shown to be associated with a lowering of the systemic vascular resistance and arterial pressure. In the present study the effectiveness of low-frequency (2 Hz) transcutaneous electrical nerve stimulation (TNS) has been examined in 46 patients, all 41-43 years of age, with a primary diagnosis of uncomplicated mild/moderate hypertension (90-115 mmHg diastolic pressure). The study was designed blind with matched controls in a TNS group and a placebo group. The blood pressure was measured objectively with an automatic monitor. In a short-term experiment TNS produced a significant lowering of systolic, mean arterial, and diastolic pressures amounting to 8 mmHg (P less than 0.01), 6 mmHg (P less than 0.01), and 4 mmHg (P less than 0.02), respectively. In a long-term study, after 2 weeks of daily stimulation, a similar depression was recorded with no stimulation on the day of examination. An eventual clinical use of the depressor effect of TNS demands further clinical research.