MYOCARDIAL GLUCOSE-METABOLISM AND ATP LEVELS ARE DECREASED 2 DAYS AFTER GLOBAL-ISCHEMIA

We hypothesized that following reversible myocardial ischemia recovery of glucose metabolism would be prolonged and would parallel recovery of high energy phosphate levels, Normothermic ischemia was achieved in dogs by aortic cross-clamping for 20 min on cardiopulnonary bypass. G lucose uptake was determined by [F-18]fluorodeoxyglucose uptake and po sitron emission tomography (PET) 1 week pre-ischemia and at 2 and 7 da ys post-ischemia (n = 8), Oxygen consumption (MVO(2)) and glucose upta ke were also measured by Fick, In a separate group of animals, adenosi ne triphosphate (ATP) and creatine phosphate (CP) levels were measured by left ventricular/septal biopsies at baseline, 2 days, and 7 days ( n = 6). Glucose uptake, as measured by PET, was reduced to 15% of base line at 2 days post-ischemia and returned to normal by 7 days post-isc hemia (P < 0.05), These results were confirmed by Fick measures of glu cose uptake. ATP levels were reduced to 49% of pre-ischemic levels at 2 days and returned to baseline by 7 days (P < 0.05), CP and MVO(2) le vels were normal at 2 and 7 days following ischemia. We conclude that reduced glucose uptake in the presence of intact oxidative metabolism suggests that glucose is not the favored substrate for ATP production following ischemia. (C) 1996 Academic Press, Inc.