Reflex activation of the sympatho‐adrenal system inhibits the gastrin release caused by electrical vagal stimulation in cats

The present study on anesthetized cats was performed to investigate how vagally induced gastrin release is influenced by simultaneous activation of the sympatho-adrenal system. The gastrin concentration in portal blood and in antral perfusates was measured with radioimmunoassay. The vagi were activated electrically and the sympatho-adrenal system by bilateral clamping of the carotid arteries. It was found that the vagally induced release of gastrin both into the circulation and into the antral lumen, was markedly inhibited (30% of control values) by simultaneous sympathetic activation, both at neutral and at acid intraantral pH. Infusions of adrenaline or noradrenaline did not mimick the effect on gastrin release induced by clamping of the carotid arteries. It is possible that the inhibitory effect of sympathetic activation on stimulated gastrin secretion is mediated via release of an inhibitory peptide, e.g. somatostatin, from the splanchnic nerves.