Cardiac and Vascular Receptors and Signal Transduction

Cellular physiological functions are regulated via signaling mechanisms in essentially any cell type of any organ within the human body. While myocardial cells are unique in that they are interconnected to each other via gap junctions and thus act as an electrical syncytium, a vast number of important cellular receptors and signal transduction pathways allow individual cells to receive and respond to various signals. These receptors and signal transduction pathways play important roles in normal cell/organ functions (their physiology), as well as in disease processes (pathophysiology). It is the aim of this chapter to review the major role and signaling mechanisms of selected physiologically and pathophysiologically important cardiac and vascular receptors, with emphasis on G protein-coupled receptors (e.g., beta-adrenergic receptors) and non-G protein-coupled receptor systems, such as guanylyl cyclase-related receptors (e.g., receptors for nitric oxide). Finally, we will discuss the importance and complexity of inflammation in the pathobiology of coronary artery disease and its treatment. Inflammation plays a very important role in cardiovascular disease. For example, device-based interventions such as coronary stenting may activate inflammation via a series of complex signaling processes. Importantly, inflammation pathways also play a central role in the elicitation of atherosclerosis, myocardial infarction, and/or heart failure.