Electroacupuncture induces antihyperalgesic effect through endothelin-B receptor in the chronic phase of a mouse model of complex regional pain syndrome type I

Abstract

Complex regional pain syndrome (CRPS) is a disorder that involves abnormal inflammation and nerve dysfunction frequently resistant to a broad range of treatments. Peripheral nerve stimulation with electroacupuncture (EA) has been widely used in different clinical conditions to control pain and inflammation; however, the use of EA in the treatment of CRPS is under investigation. In this study, we explore the effects of EA on hyperalgesia and edema induced in an animal model of chronic post-ischemia pain (CPIP model) and the possible involvement of endothelin receptor type B (ET) in this effect. Female Swiss mice were subjected to 3 h hind paw ischemia/reperfusion CPIP model. EA treatment produced time-dependent inhibition of mechanical and cold hyperalgesia, as well as edema in CPIP mice. Peripheral administration (i.pl.) of BQ-788 (10 nmol), an ET antagonist, prevented EA-induced antihyperalgesia while intrathecal administration prolonged EA's effect. Additionally, peripheral pre-treatment with sarafotoxin (SRTX S6c, 30 pmol, ET agonist) increased EA anti-hyperalgesic effect. Furthermore, the expression of peripheral ET receptors was increased after EA treatments, as measured by western blot. These results may suggest that EA's analgesic effect is synergic with ET receptor activation in the periphery, as well as central (spinal cord) ET receptor blockade. These data support the use of EA as a nonpharmacological approach for the management of CRPS-I, in an adjuvant manner to ET receptor targeting drugs.

Electroacupuncture Alleviates Mechanical Allodynia in a Rat Model of Complex Regional Pain Syndrome Type-I via Suppressing Spinal CXCL12/CXCR4 Signaling

“…35 An animal study reported that EA ameliorates the nocifensive response in a mouse model of CPIP during the chronic phase. 27 Our study further evaluated the optimal EA frequency and treatment sides and further suggested that EA can reduce the nocifensive response in both the development and maintenance phases of the animal CPIP model. These findings all support that EA can be a promising therapeutic method for CRPS-I.…”

Naprapathy attenuates neuropathic pain after brachial plexus injury

“…It can exert analgesic effect and regulatory effects on the body temperature, cardiovascular function, and respiratory function. The noxious stimuli may enhance the release of β-endorphin, which then relax the human body and the pain is then relieved (11)(12)(13). β-endorphin has been recognized as one of the neurotransmitters associated with analgesia, and thus β-endorphin expression was detected in the present study.…”

Immunoregulatory Effect of Preventive Supplementation of Omega-3 Fatty Acid in a Complex Regional Pain Syndrome Type I Model in Mice

“…The quantification of protein bands was performed by densitometry using the iBright Analysis Software (Invitrogen/Thermo Fisher Scientific, Waltham, MA, United States). The values were graphically expressed as arbitrary units in relation to the control (Saline/Sham), as briefly described ( Mazzardo-Martins et al, 2018 ).…”