Objective: Adenosine preconditioning has been shown to decrease infarct size in acute models of ischemia. We hypothesized that indices of myocardial metabolism could be preserved with adenosine pretreatment in a model of reversible ischemia. Methods: Adenosine was infused into the left anterior descending artery (LAD) for 24 minutes in eight dogs (40 μg/kg/min). Five minutes following adenosine infusion, the heart was made globally ischemic for 20 minutes at normothermia by aortic crossclamping on cardiopulmonary bypass. Adenosine triphosphate (ATP) levels were measured by drill biopsy at end-ischemia and at two days. Glucose uptake in LAD and remote regions were compared at 2 days post-op using dynamic positron emission tomography (PET) with 18-fluorodeoxyglucose. Results: ATP levels were higher in pretreated than in remote region myocardium at end-ischemia (3.34 ± 0.22 μmol/g vs. 2.71 ± 0.21, p = 0.03). Similarly, preconditioned region glucose uptake was 89% higher than remote region glucose uptake at 2 days (0.17 ± 0.02 μmol/min/g vs. 0.09 ± 0.02 μmol/min/g, p = 0.002). There was no difference between pretreated and remote region percent wall thickening as measured by 2-D echo either immediately following ischemia or at two days. Conclusion: Regional adenosine infusion protects glucose uptake and high energy phosphate levels without improvement in myocardial contractility when given prior to prolonged global ischemia.
|Original language||English (US)|
|Number of pages||6|
|Journal||Applied Cardiopulmonary Pathophysiology|
|State||Published - Dec 1 1997|
- Adenosine triphosphate
- Positron emission tomography