β-adrenergic receptors and nitric oxide generation in the cardiovascular system

Nitric oxide plays a crucial role in cardiovascular homeostasis, with important vasodilatory, anti-thrombotic and anti-atherogenic properties. beta-Adrenergic receptors (beta ARs), present on a wide variety of cardiovascular cells, including vascular endothelial cells, platelets, cardiac myocytes and leukocytes, have long been established as key players in maintaining cardiovascular homeostatic control. During the last few years a wealth of evidence has emerged which directly links stimulation of these cardiovascular beta ARs to nitric oxide (NO) generation, suggesting a new and important mechanism of adrenergic control of cardiovascular function. This review explores the cardiovascular cell systems in which this coupling of beta ARs and NO occurs, the intracellular signalling and regulatory mechanisms involved and the abnormalities in beta AR-NO oxide coupling found in cardiovascular disease states.