Effect of restraint and footshock stress and norepinephrine treatment on gastric emptying in rats.

We investigated the effects of restraint and footshock stress and norepinephrine treatment on gastric emptying. The gastric emptying was significantly inhibited by restraint stress. beta(3)-adrenergic antagonist canceled the inhibition of gastric emptying caused by restraint stress, while beta(1)-, beta(2)-, alpha(1)-, and alpha(2)-adrenergic antagonists did not affect the inhibition. Norepinephrine treatment also inhibited gastric emptying. The inhibition by norepinephrine treatment was canceled by beta(1)-, beta(2)-, and beta(3)-adrenergic antagonists, but not by alpha(1)- and alpha(2)-adrenergic antagonists. On the other hand, footshock stress did not affect gastric emptying. These results suggest that beta(3)-adrenoceptors play an important role in the inhibition of gastric emptying caused by restraint stress, while nonspecific beta-adrenoceptors are involved in that caused by norepinephrine treatment.