[Effects of a shielding antacid on changes in the gastric potential difference induced by aspirin in man]

Acetyl salicylic acid (AAS) disrupts the gastric mucosal barrier, causing a drop in the transmural potential difference (PD) and mucosal injuries. The decrease of PD correlates with endoscopic assessment and mucosal damage. The gastric PD may be used as a sensitive model for the assessement of drug-induced damage to the gastric mucosa. We have studied the effects of a shielding antacid ( Gelox ) on PD modifications induced by 500 mg of AAS in 12 healthy volunteers. Measures were performed after administration of one unit of Gelox and after a 3 day treatment period (1 unit, three times daily). Gelox induced a significant decrease of maximal PD drop (10.7 +/- 3.1 mV and 7.5 +/- 2.8 mV respectively; p less than 0.001) and of PD recovery time (p less than 0.05). After the 3 day treatment period and 14 h after the last intake, there was an increase of basal PD values and a very significant decrease (p less than 0.001) of maximal PD drop induced by AAS alone and AAS + Gelox (5.33 +/- 2.42 mV and 3.66 +/- 2.18 mV, respectively). Since the antacid effect had disappeared 14 h after the last intake of Gelox ; these results suggest an increase of the gastric mucosal barrier and a real "shielding effect".