Alcohol injury to the normal human gastric mucosa: endoscopic, histologic and functional assessment.

In 15 healthy volunteers, we studied the effect of intragastric administration of 100 ml 40% alcohol (in 10 experimental subjects) or isotonic saline (in 5 control subjects) on endoscopic appearance of the gastric mucosa, mucosal histology, luminal pH, and gastric mucosal potential difference. We found that a single dose of 40% alcohol produces rapid endoscopic changes (congestion and focal hemorrhagic lesions) and prominent histologic changes (exfoliation of the surface epithelium, edema of the lamina propria and hemorrhagic lesions associated with mucosal microvascular damage). The histologic changes were seen as early as 5 minutes after alcohol administration and occurred coincidentally with functional changes, which consisted of a sudden increase in luminal pH and a drop in the mucosal potential difference. The present study correlates the time sequence of the endoscopic, histological, and functional changes of the gastric mucosa following acute alcohol injury in normal human volunteers. This study confirms that many of the previous observations in animal models are also seen in normal human volunteers.

Effect of sucralfate on the normal human gastric mucosa. Endoscopic, histologic, and ultrastructural assessment.

Twelve healthy volunteers were given a single sucralfate tablet (1 gm) orally. For 60 min after ingestion they were examined endoscopically for the localization and disintegration of the tablet in the stomach, and biopsies were taken to determine the effect of sucralfate on the histology and ultrastructure of the normal gastric mucosa. After ingestion, the sucralfate tablet had disintegrated and firmly adhered to a relatively small mucosal area of the greater curvature covering 5 +/- 2 and 7 +/- 2 cm2 at 15 and 30 minutes, and 9 +/- 3 cm2 at 60 minutes after drug ingestion. Histologic and ultrastructural examination of the mucosa in direct contact with sucralfate revealed distinct changes in the surface epithelial cells: mucus release, vacuolization, and exfoliation of some of the cells. Endoscopy offers a unique opportunity for the study of gastroduodenal effects and disposition of orally administered drugs.

Prostaglandin protection of the human gastric mucosa against alcohol-induced injury. Endoscopic, histologic, and functional assessment.

UNLABELLED: We studied whether pretreatment with prostaglandin (16,16-dimethyl (dm) prostaglandin E2) may protect the human gastric mucosa against alcohol-induced injury. Healthy volunteers received (via an endoscope) intragastric pretreatment with either: A) placebo or B) 16,16 dm prostaglandin E2, 1 microgram/kg, and 15 min later 40 ml 60% alcohol was sprayed directly on gastric mucosa. STUDIES: endoscopic appearance of the gastric mucosa was evaluated and scored (scale 0-5) by two investigators, gastric mucosal potential difference (PD) was continuously recorded, and mucosal biopsies were obtained at 30 min after alcohol for histologic examination. Alcohol instillation in subjects pretreated with placebo (group A) produced within 30 min prominent endoscopic hemorrhagic lesions (grade 4.8 +/- 0.2). Histologic examination showed exfoliation of the surface epithelium, extensive edema of lamina propria, and deep hemorrhagic necrotic lesions in 86% +/- 10 of specimens. These morphologic changes coincided with a sudden drop in gastric PD of 42 mV. Prostaglandin pretreatment (group B) significantly reduced alcohol-induced endoscopically visible lesions (grade 3.1 +/- 0.2, P less than 0.01 vs group A). Histologically, prostaglandins reduced deep hemorrhagic erosions (4.5-fold reduction) and subepithelial hemorrhages, but did not prevent exfoliation of the surface epithelium and gastric PD drop. Thus, prostaglandin administration to human volunteers effectively reduced alcohol injury to the gastric mucosa.