Effect of gastrin on proximal gastric motor function in humans

The present study was performed to investigate the effect of gastrin on proximal gastric motor and sensory function. Ten healthy volunteers participated in three experiments performed in random order during: (A) continuous intravenous infusion of saline (control) or (B) gastrin (15 pmol kg-1 h-1) reaching postprandial serum gastrin levels or (C) gastrin infusion (15 pmol kg-1 h-1) preceded by acute acid inhibition with intravenous omeprazole. Proximal gastric function was evaluated using a barostat with stepwise pressure and volume distensions and volume measurements during set pressure (MDP + 2 mmHg). Gastrin significantly increased the intragastric volume compared to control during MDP + 2 mmHg (276 +/- 39 mL vs. 159 +/- 9 mL; P < 0.01) and reduced phasic slow volume wave frequency (from 1.4 +/- 0.1 to 0.7 +/- 0.1 per min; P < 0.01). During isobaric distensions gastrin increased gastric compliance (42 +/- 4 mL mmHg-1 vs. 31 +/- 3 mL mmHg-1; P < 0.05). These effects of gastrin infusion were completely abolished by pretreatment with omeprazole. Symptom perception decreased during gastrin infusion and was more dependent on pressure and wall tension than on volume. In conclusion: gastrin may have a role in regulating proximal gastric mechanics by inducing fundic relaxation and increasing gastric wall compliance. The effect of gastrin is dependent on acid secretion.