Metabolic oxidation of glucose during early myocardial reperfusion.
We have previously studied the relation between long-chain fatty acid and pyruvate metabolism in reperfused myocardium and noted a rapid return of fatty acid oxidation to at least preischemic values accompanied by a marked decrease in pyruvate oxidation. The purpose of the present report is to further characterize carbohydrate metabolism during reflow by describing rates of glucose oxidation using [6-14C]glucose. Oxidative performance was determined with and without preserved fatty acid utilization; the latter condition was effected by oxfenicine, which inhibits palmitoylcarnitine transferase I. In the main protocol, two groups of working swine hearts (n = 18) were perfused aerobically for 30 minutes, rendered regionally ischemic (-60 delta % in anterior descending coronary flow) for 45 minutes, and reperfused at control flows for a final 50 minutes of perfusion. An emulsion of Intralipid with heparin was administered systemically throughout the studies to augment serum fatty acids (average fatty acid values, 1.05 +/- 0.05 mumol/ml for both groups). Serum glucose was monitored and maintained at or about 100 mg/dl with additional infusions of glucose as needed. Oxfenicine (33 mg/kg) was administered systemically by bolus injection at time 0 and 60 minutes of perfusion in nine animals. Decreased mechanical performance, that is, stunning, during reflow was evident in both groups (-50 delta % in regional systolic shortening, p less than or equal to 0.05 compared with aerobic values in the control group, and -32 delta %, p less than or equal to 0.05 compared with aerobic values in treated hearts).(ABSTRACT TRUNCATED AT 250 WORDS)
Renstrom
B
B
Section of Cardiology, University of Wisconsin, Madison.
Nellis
S H
SH
Liedtke
A J
AJ
D000818:Animals; D003327:Coronary Disease / Q000503:physiopathology; D005227:Fatty Acids / Q000037:antagonists & inhibitors; D005947:Glucose / Q000378:metabolism*; D005998:Glycine / Q000494:pharmacology / Q000031:analogs & derivatives; D006003:Glycogen / Q000378:metabolism; D006321:Heart / Q000503:physiopathology; D009200:Myocardial Contraction; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D013552:Swine
D005227:Fatty Acids; C023010:4-hydroxyphenylglycine; D006003:Glycogen; D005947:Glucose; D005998:Glycine