Histamine H₁Receptor Antagonists Facilitate Electroacupuncture Analgesia

Abstract

This study investigated the influence of the histamine H receptor antagonists, chlorpheniramine (CHL) and pyrilamine, on the analgesic effects of acupuncture in mice. Nociceptive response was evaluated by the acetic acid-induced abdominal writhe test. Electroacupuncture (EA) at bilateral ST36 reduced the manifestations of acetic acid-induced abdominal writhing, whereas needle insertion without electrostimulation had no such effect. Notably, EA treatment was not associated with any analgesic effects in mice pretreated with naloxone. Low doses of CHL (0.6[Formula: see text]mg/kg; p.o.) or pyrilamine (2.5[Formula: see text]mg/kg; i.p.) as monotherapy did not affect acetic acid-induced abdominal writhing. However, when each agent was combined with EA, acetic acid-induced abdominal writhing was reduced by a greater extent when compared with EA alone. Interestingly, the effects of CHL on acupuncture analgesia were not completely reversed by naloxone treatment. Acetic acid induced increases of phospho-p38 expression in spinal cord, as determined by immunofluorescence staining and Western blot analysis. These effects were attenuated by EA at ST36 and by low doses of histamine H receptor antagonists, alone or in combination. Our findings show that relatively low doses of histamine H receptor antagonists facilitate EA analgesia via non-opioid receptors. These results suggest a useful strategy for increasing the efficacy of EA analgesia in a clinical situation.

Manual acupuncture relieves bile acid-induced itch in mice: the role of microglia and TNF-α

“…Immunofluorescence confocal microscopy was performed according to the method described by Lin et al (2016, 2018), with some modifications 23 , 33 . Tissue samples from C5-C8 spinal segments were blocked by PBS containing donkey serum 0.5% BSA and 0.4% Triton X-100 before being treated with Iba1 (1:500, #ab5076; Abcam) antibodies for 1 day.…”

Antihistamine promotes electroacupuncture analgesia in healthy human subjects: A pilot study

“…We have previously reported that chlorpheniramine monotherapy administered at 0.6 mg/kg fails to modulate pain, but when administered with EA, effectively facilitates EA analgesia in mice. 26 It has been suggested that H 1 receptor antagonist therapy may directly or indirectly facilitate opioid binding to opioid receptors, 33 interact with substance P, 34 and have antiserotonergic and/or antiadrenergic effects, 35 all of which are associated with pain modulation. Thus, antihistamine administration may mediate the pain modulation system and act in synergy with EA to facilitate its analgesic effects.…”

“…As a pilot trial, the sample size was determined by matching the numbers of study participants to the numbers of animals in our previous study. 26 …”

“… 25 Although histamine H 1 receptor antagonists are commonly used for treating allergy, we have previously reported that histamine H 1 receptor antagonism facilitates electroacupuncture (EA) analgesia in the acetic acid-induced abdominal pain model. 26 This pilot trial, therefore, sought to determine whether the histamine H 1 receptor antagonist dexchlorpheniramine (DCPA) facilitates EA analgesia in healthy volunteers. We were especially interested in comparing the effects of low- and high-dose DCPA on the modulation of EA-induced treatment efficacy and whether the combination of EA plus high-dose DCPA is superior to the other EA treatments for modulating the pain threshold.…”

Manual Acupuncture at ST37 Modulates TRPV1 in Rats with Acute Visceral Hyperalgesia via Phosphatidylinositol 3-Kinase/Akt Pathway

“…Acupuncture is widely used to alleviate visceral pain in China, owing to its ability to provide pain relief with few side effects such as addictiveness [ 33 , 34 ]. Several clinical studies have demonstrated the efficacy of acupuncture-moxibustion in visceral pain treatment [ 10 ].…”