[Dose-dependent effects of ranitidine on the transmural potential difference of the stomach]

The effect of N-[2-[[[5-[(dimethylamino)methyl]-2-furanyl]methyl]thio]ethyl]-N'-methyl-2-nitro-1,1-ethenediamine hydrochloride ranitidine and NaCl-solution in different dosages on gastric mucosal potential difference during endoscopy was examined in 92 volunteers. After bolus injections of 10-40 mg ranitidine there was a significant maximum increase in potential difference taken from different parts of the stomach and from the gastric juice. No changes were seen in the duodenal mucosal. Following bolus injections of 2.5 and 5 mg ranitidine there was a lower increase in potential difference in the gastric juice. These dosages seem to be insufficient to induce a maximum increase of potential difference in each individual.