Possible role of prostaglandins in the regulation of coronary blood flow.

Prostaglandins may represent one group of local chemical factors that control coronary perfusion and adapt it to the metabolic demands of the heart. Present study summarizes the current knowledge in this field with particular reference to prostacyclin (PGI2). The major biosynthetic pathways and their modification by drugs are briefly outlined. The sources and fates of cardiac prostaglandins are described and possible mechanisms of action discussed in both physiological and pathophysiological (myocardial ischemia) situations. Attention is focussed on the interplay between catecholamines, adenosine and PGI2. A model is presented, based on the hypothesis that adenosine from myocardial metabolism and PGI2 from vascular sites are acting in concert to antagonize sympathetic metabolic and vasoconstrictory influences and to maintain an adequate blood supply to the heart.