The Influence of Cimetidine on Basal Gastrooesophageal Sphincter Pressure, Intragastric pH, and Serum Gastrin Concentration in Normal Subjects

A pressure- and pH-sensitive probe has been constructed for simultaneous measurement of gastro-oesophageal sphincter pressure and intragastric pH. The coefficient of variation for measurements of the gastro-oesophageal sphincter was 0.24, and for the intragastric pH, 0.09. After peroral ingestion of 400 mg of cimetidine or placebo, simultaneous measurements of gastro-oesophageal sphincter pressure and intragastric pH were made at fixed time intervals, and at the same time blood samples were taken for determination of serum gastrin and serum cimetidine concentrations. No demonstrable difference was found in the time-course of the gastro-oesophageal sphincter pressure after ingestion of cimetidine or placebo. After ingestion of cimetidine a significant rise in intragastric pH (p < 0.05) occurred after 40 min, and this increased pH was maintained for the remainder of the experimental period, corresponding to a serum cimetidine concentration of over 1.00 mg/1. Similarly, there was a significant rise (p < 0.05...