| This study was designed to determine myocardial contractile function and substrate selection during hypoperfusion. Coronary perfusion pressure (CPP) was lowered in the left anterior descending coronary artery of anesthetized dogs. Glucose uptake, fatty acid uptake, and percent segment shortening (%SS) were determined with normal arterial FFA concentrations (Group 1) or with elevated concentrations (Groups 2, 3, and 4). In Group 3, glucose was removed by dialysis, and FA uptake increased and glucose uptake decreased relative to Group 1 at 40 mmHg CPP (p 0.05). Thus, although FFA are a significant energy substrate under normal conditions, the myocardium switches to glucose metabolism during hypoperfusion. However, blocking this switch does not decrease function.*.;*Originally published in MAI Vol. 38, No. 2. Reprinted here with corrected school. |
