The effect of different anticholinergics on the gastric acid response to sham feeding in man.

Modified sham feeding by the chew and spit technique stimulates gastric acid secretion at a level about 50% of peak acid output. This response is vagal and can be totally blocked by vagotomy. The effect on the acid response to modified sham feeding produced by a quaternary amine, benzilonium bromide, and a presumably more selectively acting antimuscarinic drug, pirenzepine, was compared. The drugs were given 45 min and 10 min before the start of the sham feeding, respectively. Benzilonium bromide, 1 + 1 mg, blocked 73% of the acid response to sham feeding and pirenzepine, 10 + 10 mg, blocked 48% of the response. The difference was not statistically significant. The data confirm that a part, about one third, of the acid response to sham feeding is non-cholinergic, although it is vagal.