Transmural adenosine with increased cardiac work.

In hearts with five different levels of myocardial performance there was an inverse correlation between myocardial adenosine content and coronary vascular resistance. Higher levels of oxygen consumption were associated with higher myocardial adenosine content and lower coronary vascular resistance. Adenosine was uniformly distributed across the myocardial wall under all conditions, except those involving increased oxygen consumption with concomitant decreased coronary input pressure, as was observed with isoproterenol infusion. Under these conditions the adenosine content of the inner wall was significantly higher than the outer wall.