Glucagon-like peptide-1 (7-36) amide (GLP-1) has been studied as a treatment option in diabetic patients. We investigated the effect of recombinant GLP-1 infusion on hemodynamic parameters, myocardial metabolism, and infarct size during normoxic conditions as well as during ischemia and reperfusion using an open-chest porcine heart model. In the presence of rGLP-1, interstitial levels of pyruvate and lactate decreased during ischemia and reperfusion both in ischemic and non-ischemic tissue. Moreover, rGLP-1 infusion resulted in increased plasma insulin levels and decreased blood glucose levels. Neither hemodynamic variables nor the consequent infarct size were influenced by rGLP-1 infusion. We conclude that rGLP-1 altered myocardial glucose utilization during ischemia and reperfusion. It did not exert any untoward hemodynamic effects.