Adenosine and ischemic preconditioning

Adenosine is released in large amounts during myocardial ischemia and is ca pable of exerting potent cardioprotective effects in the heart. Although th ese observations on adenosine have been known for a long time, how adenosin e acts to achieve its anti-ischemic effect remains incompletely understood. However, recent advances on the chemistry and pharmacology of adenosine re ceptor ligands have provided important and novel information on the functio n of adenosine receptor subtypes in the cardiovascular system. The developm ent of model systems for the cardiac actions of adenosine has yielded impor tant insights into its mechanism of action and have begun to elucidate the sequence of signalling events from receptor activation to the actual exerti on of its cardioprotective effect. The present review will focus on the ade nosine receptors that mediate the potent anti-ischemic effect of adenosine, new ligands at the receptors, potential molecular signalling mechanisms do wnstream of the receptor, mediators for cardioprotection, and possible clin ical applications in cardiovascular disorders.