In the last decades new pharmacodynamic properties of β-adrenoceptors have been discovered that could greatly impact in the use of β-adrenergic agents in the clinical practice. Concepts such as multiple binding sites, constitutive activity, polymorphism and intracellular signaling of β-adrenoceptors may contribute in the discovery of more efficacious pharmacological agents for treatment of heart failure and asthma. β-Adrenoceptors show a relative high constitutive activity in both cardiac and pulmonar tissues. Most β-blockers exert an inverse agonist action that could contribute to their beneficial effects in the treatment of heart failure. Recently, the existence of multiple affinity sites has been described for β1-adrenoceptor. It was proposed that β-blockers that show agonist properties at the β1L-adrenoceptors binding site may exert neutral or harmful effects when used for treatment of heart failure. Considering the cardiac effect of β1Ladrenoceptors, activation of the low-affinity state of β1-adrenoceptor could be deleterous in cardiovascular pharmacology. The ability of β2-adrenoceptor to couple to Gs or Gi-protein gives the possibility that different agonists can activate different signaling cascades. Full β2-adrenoceptor agonists would be highly useful for improvement bronchodilatation in the acute treatment of asthma. Polymorphic variants of β-adrenoceptors have profound impact in the understanding of normal physiology and pathophysiology. Genotypic characterization of patients could improve selection of patients during β-adrenergic pharmacotherapies. The aim of the present review is to describe new insights in pharmacological and biochemical properties of β-adrenoceptors and their impact on the use of β-adrenergic agents in the treatment of cardiovascular and respiratory diseases.
Keywords: Inverse agonism, agonist trafficking, β-adrenoceptors hetero-oligomerization, β-adrenoceptors polymorphisms, β- adrenergic agents
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