GP531 is a second-generation adenosine regulating agent. It is pharmacologically silent under basal conditions but increases localized endogenous adenosine during ischemia.

GP531 infusion has no effect on heart rate or mean aortic pressure but significantly decreases left ventricular end-diastolic pressure, end-diastolic volume, end-systolic volume and end-diastolic wall stress. GP531 significantly increases left ventricular EF, deceleration time of early mitral inflow velocity and the slope of end-systolic PVR without increasing MVO2.Low-dose GP531 reduces infarct size by 34% compared with vehicle and reduces the extent of the anatomic no-reflow zone by 31% compared with vehicle.?Infarct size and zone of no-reflow in the high dose are reduced by 22% and 16%, respectively.?GP531 does not affect hemodynamics or blood flow.?GP531 is effective at the lower dose in reducing the severity of ischemic/reperfusion injury, without inducing the adverse hemodynamic effects associated with adenosine administration such as bradycardia and hypotension.