Electroacupuncture reduces rectal distension-induced blood pressure changes in conscious dogs.
It has been shown that acupuncture relieves symptoms of abdominal pain and bloating in patients with irritable bowel syndrome (IBS). However, the mechanism of beneficial effects of acupuncture still remains unproven. The aim of the present study was to investigate the mechanisms of the antinociceptive effects of acupuncture in conscious dogs. We evaluated the increase in mean arterial blood pressure (MAP) caused by rectal distension as an index of visceral pain. Electroacupuncture (EA; 10 Hz) at ST-36 (lower leg), but not at BL-21 (back), significantly reduced the increase in MAP in response to rectal distension (30 and 40 cm3). The antinociceptive effect of EA at ST-36 was abolished by pretreatment with naloxone (a central and peripheral opioid receptor antagonist) but not by naloxone methiodide (a peripheral opioid receptor antagonist). These results suggest that EA at ST-36 may reduce visceral pain via central opioid pathway. Acupuncture may be useful to treat visceral hypersensitivity in IBS patients.
Iwa
Masahiro
M
Department of Surgery, Duke University and Durham Veterans Affairs Medical Center, Durham, North Carolina 27705, USA.
Strickland
Carmen
C
Nakade
Yukiomi
Y
Pappas
Theodore N
TN
Takahashi
Toku
T
D000818:Animals; D001415:Back; D001794:Blood Pressure; D002404:Catheterization; D004285:Dogs; D015671:Electroacupuncture; D005260:Female; D006614:Hindlimb; D008297:Male; D009270:Naloxone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology; D010147:Pain Measurement; D000644:Quaternary Ammonium Compounds; D012002:Rectal Diseases / Q000503:physiopathology*; D014781:Viscera / Q000503:physiopathology
D009292:Narcotic Antagonists; D000644:Quaternary Ammonium Compounds; D009270:Naloxone; C041269:N-methylnaloxone