Effect of terbutaline, a β2-adrenoreceptor agonist, on gastric acid secretion and serum gastrin concentrations in humans

Because β-adrenoreceptor agonists inhibit gastrinstimulated gastric acid secretion in animals, we postulated that the β 2 -adrenoreceptor agonist, terbutaline, would inhibit pentagastrin-stimulated acid secretion in humans. Moreover, we hypothesized that terbutaline might inhibit food-stimulated acid secretion, as gastrin is a major mediator of food-stimulated acid secretion. Subcutaneous terbutaline (0.25 mg) reduced acid secretion during intravenous infusion of a submaximal dose of pentagastrin by 30%–40% (p < 0.005), even though terbutaline increased serum gastrin levels (p < 0.05). Furthermore, subcutaneous (0.25 mg) or oral (5 mg) terbutaline, given before a homogenized steak meal was infused into the stomach, lowered mean food-stimulated acid secretion rates, despite enhanced postprandial serum gastrin concentrations. Terbutaline also increased serum gastrin concentrations in patients with Zollinger-Ellison syndrome and in vagotomized individuals. Thus, β 2 -adrenoreceptor agonists enhance gastrin release while at the same time inhibiting gastrin-stimulated acid secretion in humans.