buprenorphine and Dilatation--Pathologic

Visceral pain modulation by chronic stress in mice has been little studied. Electromyography (EMG) recording of abdominal muscle contractions, as a proxy to the visceromotor response (VMR), requires electrode implantation and post-surgical single housing (SH) which could affect the VMR to stress. To test this hypothesis, male mice had electrode implantation surgery (S) plus SH, or no surgery and were group housed (NS-GH) or single housed (NS-SH) and exposed to either water avoidance stress (WAS, 1 h/day) or left undisturbed in their home cages for 10 days. The VMR to phasic ascending colorectal distension (CRD) was assessed before (basal) and 24 h after 10 days of WAS or no stress using a surgery-free method of intraluminal colonic pressure (ICP) recording (solid-state manometry). WAS heightened significantly the VMR to CRD at 30, 45, and 60 mmHg in S-SH vs. NS-GH, but not compared to NS-SH conscious mice. Compared to basal CRD, WAS increased VMR at 60 mmHg in the S-SH group and decreased it at 30-60 mmHg in NS-GH mice, while having no effect in NS-SH mice. The average defecation during the hour of repeated WAS over 10 days was 1.9 and 2.4 fold greater in S-SH vs. NS-GH and NS-SH mice, respectively. These data indicate that the combination of S-SH required for VMR monitoring with EMG is an important component of repeated WAS-induced post-stress visceral hypersensitivity and defecation in mice.

Topics: Abdominal Muscles; Animals; Atropine; Buprenorphine; Colon; Defecation; Dilatation, Pathologic; Electrodes, Implanted; Electromyography; Hyperalgesia; Male; Mice; Mice, Inbred C57BL; Pain; Pain Threshold; Social Isolation; Stress, Psychological; Viscera; Water

Topics: Analgesics, Opioid; Animals; Buprenorphine; Dilatation, Pathologic; Gastric Dilatation; Injections, Subcutaneous; Male; Pica; Rats; Rats, Inbred F344; Rats, Wistar; Respiratory Distress Syndrome; Rodent Diseases

Narcotic substitution is now widely used. Morphine can induce a spasm of the sphincter of Oddi but dilation of bile duct has been reported only in an anecdotal case. In June 1995, we observed a first case of dilation of the common bile duct without organic obstacle in a hepatitis C virus (HCV)-infected patient who was under narcotic substitution, suggesting a causal relationship. We conducted a prospective study to evaluate the precise prevalence of bile duct abnormalities related to narcotic substitution in active intravenous drug or ex-intravenous drug users referred to our liver unit for histologic evaluation of HCV infection. We conducted a prospective study in a 30-month period of 334 HCV-infected patients, including 36 receiving narcotic substitution with methadone or buprenorphine. Biliary tract was analyzed by ultrasonography and by endoscopy ultrasound in cases of bile duct abnormalities. Of the 36 patients under narcotic substitution, 3 (8.3%) had asymptomatic dilated bile duct without organic obstacle--defined as a common bile duct > or =9 mm--compared to 1 of 298 (0.03%; p < 0.001) of those who did not receive substitution. Narcotic substitution may lead to bile duct dilation that does not require invasive diagnosis procedures.

Topics: Adult; Bile Duct Diseases; Bile Ducts; Biopsy; Buprenorphine; Common Bile Duct; Common Bile Duct Diseases; Dilatation, Pathologic; Endoscopy; Female; Hepatitis C; HIV Seronegativity; Humans; Liver; Liver Function Tests; Male; Methadone; Middle Aged; Narcotics; Prospective Studies; Substance Abuse, Intravenous; Ultrasonography