Abstract
Cigarette smoking is known to be associated with a high incidence of peptic ulcer and delay in ulcer healing. However, the mechanism is still obscure. We have reported that cigarette smoking caused a decrease in the gastric mucosal blood volume index and mucosal blood oxygenation in smokers. In this double blind study, the effects of PGEI analog (misoprostol) and cimetidine on gastric mucosal hemodynamics after cigarette smoking were investigated using reflectance spectrophotometry. Eighteen volunteers were fasted overnight, and either 200, ug of misoprostol, 200mg of cimetidine or placebo was administered orally. The spectra were taken from the mucosa of the lesser curvature of the lower corpus every 5 min for 20 min after drug administra-tion. Thereafter, five puffs of a cigarette smoking were taken. The spectra were taken after each puff, and at 5 min and 10 min after the fifth puff. The indices of gastric mucosal blood volume and oxygen saturation of hemoglobin were calculated from the spectrum. The average percent decrease of gastric mucosal blood volume and gastric mucosal oxygen saturation of hemoglobin after smoking were, respectively, -9.2±2.9%, -9.4±2.7% in placebo group, -5.9 ± 0.9%, -9.0 ± 0.9% in cimetidine group. Because misopros-tol prevented completely smoking-induced decrease of gastric mucosal blood volume and oxygen saturation of hemoglobin (average decrease= -0.8±5.5%, +3.3±3.4%), miso-prostol maintained the gastric mucosal blood volume during smoking. In conclusion, cigarette smoking decreases the gastric mucosal blood volume index and mucosal oxygenation, but pretreatment with a PGEI analog, misoprostol, prevents this smoking-induced decrease.
