Objective: To explore the changes of mRNA and protein expressions of glycolytic and fatty acid metabolic enzymes early after acute myocardial ischemia.
Methods: Twelve dogs were randomly divided into 3 groups (sham, 20 min ischemia and 40 min ischemia, n = 4 each). Myocardial samples from ischemic and nonischemic zone were obtained for histology examination, and the mRNA expressions for Phosphofructokinase (PFK), Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), GLUT1, GLUT4, Medium-chain acyl-CoA dehydrogenase (MCAD) and Heart-fatty acid binding protein (H-FABP) were determined by Real Time PCR-SYBR Green RT-PCR. GLUT1 protein expression was determined by immunohistochemistry. The apoptotic cardiomyocytes was evaluated by TUNEL.
Results: Compared to sham hearts, H-FABP mRNA was decreased in nonischemic and ischemic zone (P < 0.05) while GLUT1 mRNA expression was significantly increased in nonischemic and ischemic zone (P < 0.05) in dogs underwent 20 and 40 min ischemia. PFK mRNA tended to be higher in ischemic myocardium (P = 0.065) and GAPDH, MCAD as well as GLUT4 remained unchanged post ischemia (all P > 0.05). Positive GLUT1 protein staining was visualized in ischemic myocardium of hearts underwent 20 and 40 min ischemia. The myocardial apoptosis cells was 6.4% +/- 0.9% in sham hearts, 28.0% +/- 3.7% in hearts underwent 20 min ischemia (P < 0.05 vs. sham) and 38.4% +/- 1.9% in hearts underwent 40 min ischemia (P < 0.05 vs. sham).
Conclusions: Significant down and up-regulated glycolytic and fatty acid metabolic enzymes early after myocardial ischemia suggested that these enzymes might play an important role in acute myocardial ischemia.