[The nature of differences in beta-adrenergic receptors]

Results of investigation of the affinity between teranol (practalol), alpheprol (alprenolol), propranolol to beta-adrenoreceptors of various organs confirmed the division of these receptors into two subtypes. The action of isadrin on beta1-adrenoreceptors of the myocardium and smooth muscles of the gastrointestinal tract was accompanied by changes in Ca2+ entrance into the cells. With the action of isadrin on beta2-adrenoreceptors of the trachea and the vessels there was seen an intensification of the Ca2+ ions from the cells and a reduction of the smooth muscle tone.