Effect of pentagastrin and cimetidine on gastric blood flow measured by laser Doppler flowmetry

Endoscopic laser Doppler flowmetry has been used to study the effect of the secretagogue pentagastrin and the H2-receptor antagonist cimetidine on gastric blood flow in 24 healthy subjects. The subcutaneous injection of pentagastrin, 0.6 micrograms/kg body weight, caused a significant increase in gastric acid secretion. This increase did not provoke any significant change in gastric blood flow, measured in seven defined areas of the oesophagus and stomach. Furthermore, no significant correlation was found between the level of basal and maximal acid secretion and blood flow. The infusion of 200 mg cimetidine caused a significant reduction of gastric blood flow in five of the seven investigated areas (P less than 0.05 and P less than 0.01). Cimetidine had no effect on blood pressure or skin blood flow, measured by laser Doppler flowmetry. The study was performed without previous stimulation of acid secretion, and blood flow reduction was measured in both the corpus and the antrum of the stomach. The effect of cimetidine is therefore hardly a result of the acid-reducing effect of the drug. In this study no significant relationship could be shown between the gastric wall blood flow and acid secretion.