Effects of induced hypotension with ATP on myocardial ischemia and reperfusion injury

Abstract

To elucidate the effects of induced hypotension with ATP on hemodynamics and myocardial infarct size following ischemia and reperfusion, we studied anesthetized rabbits received regional ischemia by 30 min of the left anterior descending artery (LAD) occlusion followed by 3 hrs of reperfusion under ketamine/xylazine anesthesia. The animals were randomly assigned to a control group, and ATP treatment group, in which a continuous infusion of ATP (5.0 mg⋅kg^-1⋅h^-1) was initiated 30 min prior to ischemia to reduce mean arterial blood pressure by approximately 20% throughout ischemia and reperfusion. Hemodynamic changes were measured throughout the experiment. The area at risk was delineated by Evans blue, and infarct size was determined by tetrazolium staining at the end of the experiment by re-ligation of LAD. The area at risk showed no significant difference between two groups; Infarct size/area at risk in the ATP rabbits was significantly reduced to 49.0±4.2% from 61.9±7.1 in control.
These data suggest that ATP has protective effects against myocardial ischemia in an in situ rabbit model.