[An investigation on adrenergic receptors in rat stomach]

The effects of phentolamine and propranolol on intragastric pressure were observed in 46 Wistar rats. The results showed that: (1) phentolamine did not cause significant changes in the intragastric pressure of intact rats, but, it could obviously decrease the intragastric pressure of rats with vagotomy. (2) propranolol increased the intragastric pressure of intact rats or rats with vagotomy. We concluded that (1) tonic action of adrenergic nerves in stomach is mainly inhibitory; (2) beta-adrenoceptors, which may be present on the smooth muscle of stomach mediate sympathetic inhibition; (3) alpha-adrenoceptors, which come into play through vagus, mediate inhibition, but alpha-adrenoceptors, which may be present on the smooth muscle, mediate sympathetic excitation.