ADENOSINE RECEPTORS AND CARDIOVASCULAR FUNCTION

Adenosine exerts pronounced cardiac and vascular effects. Distinct receptors, present on the endothelium and vascular and cardiac myocytes, mediate the various cardiovascular effects of adenosine. The A1 and the A2 subtypes of adenosine receptor are coupled to different G proteins, second messengers, and physiologic responses. Recent cloning of the two subtypes of adenosine receptor should enhance our understanding of the structure, function, and regulation of these receptors and should facilitate discovery of new subtypes that may be expressed in a tissue-specific manner. These molecular advances should also provide insights into the mechanism of the cardiovascular action of adenosine, which is gaining greater clinical usefulness.