Vagal stimulation augments maximal (penta) gastrin-stimulated acid secretion in humans

Since the late sixties, the pentagastrin test has been the standard method to examine maximal gastric acid secretion in humans. However, studies on ra ts and dogs have shown that maximal pentagastrin-stimulated acid secretion can be augmented by concomitant cholinergic stimulation. The aim of this st udy was to examine whether the combined stimulation of the vagal nerves and pentagastrin infusion could increase maximal gastric acid secretion compar ed with pentagastrin alone. Eight healthy medical students (seven males) we re included in the study. Gastric acid secretion was determined thrice in e ach subject. On day one, pentagastrin (6 mu g kg(-1) h(-1)) was infused. On day two, insulin-induced hypoglycaemia (plasma glucose approximate to 2.3 mM during 30 min) was obtained by applying the glucose clamp technique. On day three, pentagastrin infusion and insulin induced-hypoglycaemia were com bined. The combination of insulin-induced hypoglycaemia and pentagastrin in fusion increased peak acid output about 20% (P = 0.018) compared with penta gastrin alone. The hypoglycaemia did not cause significant release of gastr in. It is concluded that vagal stimulation of gastric acid secretion may be safely obtained by insulin-induced hypoglycaemia when applying the glucose clamp technique. In addition, maximal pentagastrin-stimulated acid secreti on does not represent the maximal acid secretory capacity in humans.