816 research outputs found
Acute effects of N-terminal progastrin fragments on gastric acid secretion in man
We previously identified an Nâterminal fragment of progastrin in human antrum and plasma, where it circulates in high concentrations. In this study, we examined the effects of Nâterminal progastrin fragments on gastric acid secretion by infusion in healthy individuals. Increasing doses of progastrin fragment 1â35 were infused intravenously during constant gastric acid stimulation by gastrinâ17. In addition, the effects of progastrin fragment 1â35, fragment 6â35, and fragment 1â19 on gastrinâ17 stimulated acid secretion were tested. The gastrinâ17 stimulated acid secretion decreased 30% after administration of a high dose of progastrin fragment 1â35 (P < 0.05). In extension, a 1âh infusion of fragment 1â35 also decreased gastric acid output. In contrast, fragment 6â35 did not affect acid secretion, and a single infusion of gastrinâ17 alone did not reveal fading of gastric acid output during the time course of the experiments. The results show that Nâterminal fragments of progastrin may acutely affect gastrinâstimulated gastric acid secretion in vivo. Structureâfunction analysis suggests that the Nâterminal pentapeptide of progastrin is required for the effect
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