Chronic parenterally administered nicotine and stress- or ethanol-induced gastric mucosal damage in rats.
Mini-osmotic pumps containing solutions of either 0.9% NaCl (infused at the rate of 0.5 microliter/h) or nicotine (infused in doses of 0.224, 1.03 or 1.88 mg/kg per day) were implanted s.c. into rats 12 days before experimentation. The alkaloid increased solid food consumption, but fluid intake and average weight gain were similar among the animals given saline or nicotine. Chronic nicotine treatment dose dependently intensified cold (4 degrees C)-restraint stress-induced ulceration and increased mast cell degranulation. Oral administration of 40% ethanol to nicotine-treated animals also produced greater mucosal damage; mast cell degranulation by ethanol was significantly worsened after alkaloid treatment. These findings show that the stress ulcer-intensifying action of the alkaloid is mainly through a systemic mechanism. In the case of ethanol-evoked mucosal damage, in addition to a topical effect, stimulation of the stomach wall ganglia is likely to participate in the exaggerated post-vagal ulcerogenic responses as seen in stress.
Wong
D
D
Department of Pharmacology, Faculty of Medicine, University of Hong Kong.
Ogle
C W
CW
D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects; D003080:Cold Temperature; D004326:Drinking / Q000187:drug effects; D004343:Drug Implants; D004435:Eating / Q000187:drug effects; D000431:Ethanol; D005260:Female; D007279:Injections, Subcutaneous; D008407:Mast Cells / Q000187:drug effects; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D013276:Stomach Ulcer / Q000139:chemically induced / Q000209:etiology / Q000473:pathology*; D013315:Stress, Psychological / Q000503:physiopathology*; D015430:Weight Gain / Q000187:drug effects
D004343:Drug Implants; D000431:Ethanol; D009538:Nicotine