Effect of adrenergic blocking agents on plasma gastrin and secretin levels in man

The effect of adrenergic blocking agents on gastrin and secretin secretion before and after a bolus arginine injection (arginine pulse) was investigated in normal subjects. Repeated arginine pulses given at 30-minute intervals caused abrupt and almost identical rises of plasma gastrin with each pulse. On the other hand, plasma secretin levels were unchanged by repeated injections of arginine. The increase in plasma gastrin induced by arginine pulse was significantly suppressed by the infusion of beta-adrenergic blocking agent, propranolol, while the infusion of alpha-adrenergic blocking agent, phentolamine tended to enhance the arginine-induced gastrin secretion slightly but not significantly. Whereas, the infusion of neither phentolamine nor propranolol had significant influence on secretin secretion. These results suggest that alpha- and beta-adrenergic receptors play an important role in the regulation of arginine-induced gastrin secretion.