[The role of adrenoreceptors in the manifestation of the smooth-muscle reactions of the pyloric sphincter and small intestine to acute blood loss].

Acute blood loss evoked an increase in the spike activity of the pyloric sphincter' smooth muscles, those of the duodenum and ileum. No such effect was found in joint blockade of alpha- and beta-adrenoreceptors. The increase in the spike activity seems to be due to an effect of endogenous catecholamines upon activating alpha- and beta-adrenoreceptors of the pyloric sphincter, duodenum and ileum.