Entrez PubMed
Overview
Help | FAQ
New/Noteworthy
PubMed Services
Journal Browser
MeSH Browser
Single Citation Matcher
Batch Citation Matcher
Clinical Queries
Cubby
Related Resources
Order Documents
Grateful
Med
Consumer
Health
Clinical Alerts
ClinicalTrials.gov
Privacy Policy
|
 |
-
Nitric oxide mediates a therapeutic effect of nicotine in
ulcerative colitis
Green JT, Richardson C, Marshall
RW, Rhodes J, McKirdy HC, Thomas GA, Williams GT
Department
of Gastroenterology, University Hospital of Wales, Cardiff, UK;
Department of Surgery, University Hospital of Wales, Cardiff, UK;
Department of Pharmacology and Therapeutics, University of Wales College
of Medicine, Cardiff, UK; Dep.
[Record supplied by
publisher]
BACKGROUND: Ulcerative colitis is a condition of
nonsmokers in which nicotine is of therapeutic benefit. AIMS: To examine
the in vitro effect of nicotine on colonic smooth muscle activity and
the role of nitric oxide (NO) as a mediator. METHODS: Nicotine, 1-10
&mgr;M, was administered to strips of circular muscle from the
distal sigmoid colon of 9 patients with active ulcerative colitis and 18
with colorectal cancer. The effect of electrical field stimulation (EFS)
was examined before nicotine was added. Finally L-NAME, a NO synthetase
inhibitor, was added before nicotine was administered again. RESULTS:
Muscle strips developed similar spontaneous resting tone. In response to
EFS, ulcerative colitis tissue developed lower tensions than the
controls. Nicotine significantly reduced the resting tone and peak
tension after EFS, with a greater effect in controls. With L-NAME, peak
tensions were increased more in ulcerative colitis than controls, and
nicotine produced a much smaller reduction. CONCLUSIONS: Nicotine
reduces circular muscle activity, predominantly through the release of
nitric oxide-this appears to be 'up-regulated' in active ulcerative
colitis. These findings may explain some of the therapeutic benefit from
nicotine (and smoking) in ulcerative colitis and may account for the
colonic motor dysfunction in active disease.
PMID: 11069313
|