Effects of electroacupuncture on oxaliplatin-induced neuropathic cold hypersensitivity in rats

J Physiol Sci. 2014 Mar;64(2):151-6. doi: 10.1007/s12576-013-0297-0. Epub 2013 Oct 26.

Abstract

This study investigated whether and how electroacupuncture (EA) attenuates cold hypersensitivity (allodynia) in a rat model of oxaliplatin-induced neuropathic pain. Cold allodynia [evaluated by immersing the tail into cold water (4 °C) and measuring the withdrawal latency] was induced 3 days after an oxaliplatin administration (6 mg/kg, i.p.). EA stimulation (2/100 Hz, 0.3-ms pulse duration, 0.2-0.3 mA) was delivered to ST36 acupoint or non-acupoint for 20 min. Low-frequency (2 Hz) EA at ST36 relieved cold allodynia more effectively than high-frequency EA at ST36 or low-frequency EA at non-acupoint. Naloxone (opioid antagonist, 2 mg/kg, i.p.) completely blocked such EA-induced anti-allodynia, whereas phentolamine (α-adrenergic antagonist, 2 mg/kg, i.p.) did not. Moreover, plasma β-endorphin levels significantly increased right after the end of EA and subsequently decreased. These results indicate that low-frequency EA at ST36 in rats has a marked relieving effect on oxaliplatin-induced cold allodynia that is mediated by the endogenous opioid, but not noradrenergic, system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic alpha-Antagonists / pharmacology
  • Animals
  • Behavior, Animal
  • Cold Temperature*
  • Disease Models, Animal
  • Electroacupuncture*
  • Hyperalgesia / blood
  • Hyperalgesia / chemically induced
  • Hyperalgesia / physiopathology
  • Hyperalgesia / therapy*
  • Male
  • Naloxone / pharmacology
  • Narcotic Antagonists / pharmacology
  • Organoplatinum Compounds*
  • Oxaliplatin
  • Pain Threshold
  • Phentolamine / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Reaction Time
  • Time Factors
  • beta-Endorphin / blood

Substances

  • Adrenergic alpha-Antagonists
  • Narcotic Antagonists
  • Organoplatinum Compounds
  • Oxaliplatin
  • Naloxone
  • beta-Endorphin
  • Phentolamine