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Spezia Adachi LN, Vercelino R, de Oliveira C, Scarabelot VL, de Souza A, Medeiros LF, Cioato SG, Caumo W, Torres ILS. Isoflurane and the Analgesic Effect of Acupuncture and Electroacupuncture in an Animal Model of Neuropathic Pain. J Acupunct Meridian Stud 2018; 11:97-106. [PMID: 29436370 DOI: 10.1016/j.jams.2018.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 12/17/2022] Open
Abstract
The present study aimed to determine whether isoflurane interferes with the analgesic effects of acupuncture (Ac) and electroacupuncture (EA), using a neuropathic pain (NP) rat model. In total, 140 male Wistar rats were used; isoflurane-induced nociceptive response was evaluated using the von Frey test, serum calcium-binding protein β (S100β) levels and nerve growth factor (NGF) levels in the left sciatic nerve. The NP model was induced by chronic constriction injury of the sciatic nerve at 14 days after surgery. Treatment was initiated after NP induction with or without isoflurane anesthesia (20 min/day/8 days). The von Frey test was performed at baseline, 14 days postoperatively, and immediately, 24 h, and 48 h after the last treatment. Results of the nociceptive test and three-way analysis of variance were analyzed by generalized estimating equations, the Bonferroni test, followed by Student-Newman-Keuls or Fisher's least significant difference tests for comparing biochemical parameters (significance defined as p ≤ 0.05). At baseline, no difference was noted in the nociceptive response threshold among all groups. Fourteen days after surgery, compared with other groups, NP groups showed a decreased pain threshold, confirming establishment of NP. Ac and EA enhanced the mechanical pain threshold immediately after the last session in the NP groups, without anesthesia. Isoflurane administration caused increased nociceptive threshold in all groups, and this effect persisted for 48 h after the last treatment. There was an interaction between the independent variables: pain, treatments, and anesthesia in serum S100β levels and NGF levels in the left sciatic nerve. Isoflurane enhanced the analgesic effects of Ac and EA and altered serum S100β and left sciatic nerve NGF levels in rats with NP.
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Affiliation(s)
- Lauren N Spezia Adachi
- Graduate Program in Medicine, Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Animal Experimentation Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Rafael Vercelino
- Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Centro Universitário FADERGS, Health and Wellness School Laureate International Universities, Porto Alegre, RS, Brazil
| | - Carla de Oliveira
- Graduate Program in Medicine, Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Animal Experimentation Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Vanessa L Scarabelot
- Graduate Program in Biological Sciences, Physiology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Animal Experimentation Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Andressa de Souza
- Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Animal Experimentation Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Liciane F Medeiros
- Graduate Program in Biological Sciences, Physiology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Animal Experimentation Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Stefania G Cioato
- Graduate Program in Biological Sciences, Pharmacology and Therapeutics, Institute of Basic Health Sciences, Universidade Federal Rio Grande do Sul, Porto Alegre, RS, 90050-170, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Animal Experimentation Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil
| | - Wolnei Caumo
- Graduate Program in Medicine, Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Iraci L S Torres
- Graduate Program in Medicine, Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Biological Sciences, Physiology, Institute of Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Biological Sciences, Pharmacology and Therapeutics, Institute of Basic Health Sciences, Universidade Federal Rio Grande do Sul, Porto Alegre, RS, 90050-170, Brazil; Laboratory of Pain Pharmacology and Neuromodulation: Preclinical Researchs, Department of Pharmacology, Institute of Basic Health Sciences, Universidade Federal Do Rio Grande Do Sul, Porto Alegre, RS, Brazil; Animal Experimentation Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
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Electroacupuncture in conscious free-moving mice reduces pain by ameliorating peripheral and central nociceptive mechanisms. Sci Rep 2016; 6:34493. [PMID: 27687125 PMCID: PMC5043286 DOI: 10.1038/srep34493] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 09/14/2016] [Indexed: 11/08/2022] Open
Abstract
Integrative approaches such as electroacupuncture, devoid of drug effects are gaining prominence for treating pain. Understanding the mechanisms of electroacupuncture induced analgesia would benefit chronic pain conditions such as sickle cell disease (SCD), for which patients may require opioid analgesics throughout life. Mouse models are instructive in developing a mechanistic understanding of pain, but the anesthesia/restraint required to administer electroacupuncture may alter the underlying mechanisms. To overcome these limitations, we developed a method to perform electroacupuncture in conscious, freely moving, unrestrained mice. Using this technique we demonstrate a significant analgesic effect in transgenic mouse models of SCD and cancer as well as complete Freund's adjuvant-induced pain. We demonstrate a comprehensive antinociceptive effect on mechanical, cold and deep tissue hyperalagesia in both genders. Interestingly, individual mice showed a variable response to electroacupuncture, categorized into high-, moderate-, and non-responders. Mechanistically, electroacupuncture significantly ameliorated inflammatory and nociceptive mediators both peripherally and centrally in sickle mice correlative to the antinociceptive response. Application of sub-optimal doses of morphine in electroacupuncture-treated moderate-responders produced equivalent antinociception as obtained in high-responders. Electroacupuncture in conscious freely moving mice offers an effective approach to develop a mechanism-based understanding of analgesia devoid of the influence of anesthetics or restraints.
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Wang Y, Hackel D, Peng F, Rittner HL. Long-term antinociception by electroacupuncture is mediated via peripheral opioid receptors in free-moving rats with inflammatory hyperalgesia. Eur J Pain 2013; 17:1447-57. [PMID: 23649949 DOI: 10.1002/j.1532-2149.2013.00325.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND Electroacupuncture (EA) has been widely accepted and applied as an important acupuncture-related technique for acupuncture analgesia (AA) research. The involvement of opioid peptides and receptors in acute AA has been shown via pre-EA application of opioid receptor/peptide antagonists. In this study, we intended to reproducibly institute acupoint position and needling excluding influences from anaesthesia or restrainers on rats with complete Freund's adjuvant (CFA) hind paw inflammatory pain, as well as to explore opioid-dependency and anti-inflammatory effects in sustained acupuncture analgesia. METHODS Accurate position and needling approach on acupoint GB30 was modelled by computer-based three-dimensional (3D) images and followed by an optimal EA treatment protocol (100 Hz, 2-3 mA, 20 min) at 0 and 24 h post-CFA in conscious free-moving rats. Opioid receptor antagonists, naloxone (NLX) and naltrindole (NTI) were applied intraplantarly post-EA at late phase (96 h) of CFA. Nociceptive thresholds were assessed by paw pressure threshold (Randall-Sellito) or paw withdrawal latency (Hargreaves), and anti-inflammatory effects were evaluated by measurement of plantar temperature and paw volume. RESULTS EA elicited significant sustained mechanical and thermal antinociception up to 144 h. Mechanical antinociception of EA was suppressed by peripheral intraplantar application of NLX and NTI. EA also reduced paw temperature and volume during the same time frame indicating anti-inflammatory effects. CONCLUSIONS By employing a reproducible EA treatment model on GB30 in free-moving rats, we demonstrated the involvement of peripheral opioid receptors mediated EA-induced long-term antinociception. Future studies should examine the specific neuroimmunological connection of EA-induced sustained antinociception in inflammation.
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Affiliation(s)
- Y Wang
- Department of Anesthesiology, University Hospital of Würzburg, Germany
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Silva ML, Silva JR, Prado WA. The antinociceptive effect of electroacupuncture at different depths of acupoints and under the needling surface. Chin Med 2012; 7:3. [PMID: 22369266 PMCID: PMC3305550 DOI: 10.1186/1749-8546-7-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 02/27/2012] [Indexed: 11/12/2022] Open
Abstract
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.
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Affiliation(s)
- Marcelo L Silva
- Department of Pharmacology, Faculty of Medicine of Ribeirão Preto-USP, Avenue Bandeirantes 3900, CEP 14049-900 Ribeirão Preto, SP, Brazil.
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