naloxone and Rectal-Diseases

Colonic inertia and outlet obstruction are a major problem of constipation affecting almost solely women and are characterised by an extreme slowness of colonic transit time (less than 80 percent of the markers eliminated in five days) and by a lack of relaxation and a contraction of pelvic muscles, mainly of the pubo-rectalis, during defecation. This syndrome is associated with a high frequency of gynecological diseases (first described in 1908 by Arbuthnot Lane), galactorrhea, urological abnormalities, abnormal manometric oesophageal recordings, Raynaud's phenomenon, idiopathic oedema, orthostatic hypotension and neurological symptoms. A distinctive abnormality of the colonic myenteric plexus has been described. Medical treatment of the affection is without effect, with the exception, perhaps, of the prescription of naloxone. In the absence of other therapeutic means, subtotal colectomy with ileo-rectal and coeco-rectal anastomosis may give relative improvement.

Topics: Colectomy; Constipation; Defecation; Female; Gastrointestinal Motility; Humans; Intestinal Obstruction; Naloxone; Rectal Diseases; Syndrome; Time Factors

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.

Topics: Animals; Back; Blood Pressure; Catheterization; Dogs; Electroacupuncture; Female; Hindlimb; Male; Naloxone; Narcotic Antagonists; Pain; Pain Measurement; Quaternary Ammonium Compounds; Rectal Diseases; Viscera