Effect of pirenzepine on L--amino acids stimulated gastric acid secretion and serum gastrin levels in peptic ulcer disease in men.

This report tests in men the effect of Pirenzepine on L-Amino acids stimulated gastric secretion and serum gastrin levels in order to evaluate the true antimuscarinic selective properties of this drug. Since L-Amino acids given intravenously stimulate gastric acid secretion by a mechanism of action selective on the cholinergic receptors of the gastric parietal cells, not mediated through the vagus nerve, gastrin or other gut hormones. Pirenzepine should be an L-Amino acids antagonist as far as the gastric acid secretion is concerned. By confirming this presumed antagonism between Pirenzepine and L-Amino acids given intravenously, this report points out in men the selective antimuscarinic effect of this anti ulcer drug on the high affinity muscarinic receptors of the gastric parietal cells. Finally a decrease in gastrin serum levels was observed after the i.v. administration of Pirenzepine and this could be explained by a possible effect of blockade of this drug on the cholinergic receptors of the antral G cells, but these data need further experimental confirm. Attention is then paid to the different mechanism of action between Pirenzepine, H2 receptors antagonist drugs and other anti ulcer drugs on healing gastric or duodenal peptic ulcers.