Involvement of spinal muscarinic and serotonergic receptors in the anti-allodynic effect of electroacupuncture in rats with oxaliplatin-induced neuropathic pain.
10.4196/kjpp.2016.20.4.407
- Author:
Ji Hwan LEE
1
;
Donghyun GO
;
Woojin KIM
;
Giseog LEE
;
Hyojeong BAE
;
Fu Shi QUAN
;
Sun Kwang KIM
Author Information
1. Department of Science in Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Korea. skkim77@khu.ac.kr
- Publication Type:Original Article
- Keywords:
Acetylcholine;
Cold allodynia;
Electroacupuncture;
Oxaliplatin;
Serotonin
- MeSH:
Acetylcholine;
Acupuncture Points;
Animals;
Electroacupuncture*;
Hyperalgesia;
Injections, Intraperitoneal;
Neuralgia*;
Rats*;
Receptors, Muscarinic;
Serotonin;
Tail;
Water
- From:The Korean Journal of Physiology and Pharmacology
2016;20(4):407-414
- CountryRepublic of Korea
- Language:English
-
Abstract:
This study was performed to investigate whether the spinal cholinergic and serotonergic analgesic systems mediate the relieving effect of electroacupuncture (EA) on oxaliplatin-induced neuropathic cold allodynia in rats. The cold allodynia induced by an oxaliplatin injection (6 mg/kg, i.p.) was evaluated by immersing the rat's tail into cold water (4℃) and measuring the withdrawal latency. EA stimulation (2 Hz, 0.3-ms pulse duration, 0.2~0.3 mA) at the acupoint ST36, GV3, or LI11 all showed a significant anti-allodynic effect, which was stronger at ST36. The analgesic effect of EA at ST36 was blocked by intraperitoneal injection of muscarinic acetylcholine receptor antagonist (atropine, 1 mg/kg), but not by nicotinic (mecamylamine, 2 mg/kg) receptor antagonist. Furthermore, intrathecal administration of M(2) (methoctramine, 10 µg) and M(3) (4-DAMP, 10 µg) receptor antagonist, but not M(1) (pirenzepine, 10 µg) receptor antagonist, blocked the effect. Also, spinal administration of 5-HT(3) (MDL-72222, 12 µg) receptor antagonist, but not 5-HT(1A) (NAN-190, 15 µg) or 5-HT(2A) (ketanserin, 30 µg) receptor antagonist, prevented the anti-allodynic effect of EA. These results suggest that EA may have a signifi cant analgesic action against oxaliplatin-induced neuropathic pain, which is mediated by spinal cholinergic (M(2), M(3)) and serotonergic (5-HT(3)) receptors.
