LAUSR

ABSTRACT Adrenergic receptors (ARs) are G-protein coupled receptors that are stimulated by catecholamines to induce a wide array of physiological effects across tissue types. Both α1- and β-ARs are found on cardiomyocytes and regulate cardiac contractility and hypertrophy through diverse molecular pathways. Acute activation of cardiomyocyte β-ARs increases heart rate and contractility as an adaptive stress response. However, chronic β-AR stimulation contributes to the pathobiology of heart failure. In contrast, mounting evidence suggests that α1-ARs serve protective functions that may mitigate the deleterious effects of chronic β-AR activation. Here we will review recent studies demonstrating that α1- and β-ARs differentially regulate mitochondrial biogenesis and dynamics, mitochondrial calcium handling, and oxidative phosphorylation in cardiomyocytes. We will identify potential mechanisms of these actions and focus on the implications of these findings for the modulation of contractile function in the uninjured and failing heart. Collectively we hope to elucidate important physiological processes through which these well-studied and clinically relevant receptors stimulate and fuel cardiac contraction to contribute to myocardial health and disease.