The influence of smoking and intravenous nicotine on gastric mucus.

Smoking predisposes to peptic ulcer. Bound N-acetylneuraminic acid (NANA) is an essential constituent of mucus. In order to examine whether smoking changes gastric mucus secretion, the concentration of N-acetylneuraminic acid was measured in the gastric juice of 10 non-smokers and 10 smokers. Gastric juice was aspirated during intravenous infusion of 0.67 microgram/kg/hr pentagastrin given alone or together with 5 micrograms/kg/hr nicotine. Instead of intravenous nicotine, the 10 smokers smoked 5 cigarettes over a period of 2 hours. In the fasting gastric juice and during infusion of pentagastrin the gastric concentration and output of bound N-acetylneuraminic acid were similar in smokers and in non-smokers. Acute nicotine administered intravenously or by smoking left gastric output of bound N-acetylneuraminic acid unaffected. It is concluded that neither chronic nor acute consumption of nicotine affects gastric turnover or adherence of mucus to the mucosa.