Beta-Adrenoreceptor Overview
Beta-adrenoreceptors (β-adrenoceptors) are a class of G protein-coupled receptors (GPCRs) that mediate the physiological effects of catecholamines, primarily norepinephrine and epinephrine. They play critical roles in regulating cardiovascular, respiratory, metabolic, and central nervous system functions. There are three main subtypes: β1, β2, and β3, each with distinct tissue distributions and physiological roles. Activation leads to increased cAMP production and downstream signaling. Ligands include endogenous catecholamines and synthetic agonists/antagonists. Beta-blockers are widely used for treating cardiovascular conditions and anxiety, while beta agonists serve as bronchodilators.
Mechanism of Action
Agonist binding leads to stimulation of adenylyl cyclase, increasing intracellular cAMP, activating PKA, and leading to diverse cellular responses. Antagonists block the receptor, preventing activation by endogenous ligands.
Biological Functions
Disease Associations
Safety Considerations
- Beta-blockers can cause bradycardia, hypotension, and bronchospasm.
- Beta-agonists can cause tachycardia, tremors, and anxiety.