Some aspects of the pharmacology of beta-adrenorecptor blockers.
The pharmacodynamic properties of a beta-blocker are mainly determined by its affinity to beta1 and beta2-receptors respectively and by its intrinsic activity. It is suggested that there is no absolute organ separation of the two receptor sub-types. Instead both beta1 and beta2-receptors are involved in the mediation of the same effect. The frequency distribution ratio of beta1/beta2-receptors varied markedly among various effector responses. A non-selective and a beta1-selective blocker may have different haemodynamic effects when the levels of circulating adrenaline are high, because of their markedly different potency in inhibiting the beta2-mediated vasodilator effect of adrenaline. Data are presented which suggest the existence of a presynaptic beta1-receptor mediating a positive feedback mechanism on neuronal release of noradrenaline.
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D002415:Cats; D004285:Dogs; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D009928:Organ Specificity; D011412:Propanolamines / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; D011433:Propranolol; D009638:Norepinephrine