| Abstract: | The effects of bile acids (deoxycholic, cholic and dehydrocholic) were studied on the action of certain autonomic system drugs (isoprenaline, adrenaline, noradrenaline and acetylcholine). It was also tried to explain the causes of these changes in the light of the results of experiments with the widely used antagonists of adrenergic and cholinergic receptors. The experiments were carried out on isolated rat intestine by the method of Magnus. It was found that bile acids decreased the relaxing effect of isoprenaline and caused inversion of the action of adrenaline and noradrenaline on the intestine. Changes in the action of catecholamines are caused by stimulation of alpha-adrenergic receptors enhanced by bile acids, with a simultaneous decreased stimulation of beta-receptors. Bile acids cause also an increase of the effect of acetylcholine on the intestine. |
