Stimulation of Carbohydrate Metabolism Reduces Hypothermia-induced Calcium Load in Fatty Acid-perfused Rat Hearts

• Published in: Journal of molecular and cellular cardiology 1997-02, Vol.29 (2), p.527-534
• Main Authors: Aasum, Ellen, Steigen, Terje K., Larsen, Terje S.
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - metabolism; Animals; Calcium - metabolism; Calcium - pharmacokinetics; Carbohydrate Metabolism; Cardiac Output; Dichloroacetate; Fatty Acids - metabolism; Fatty Acids - pharmacology; Glucose - metabolism; Glycogen - metabolism; Glycolysis; Hypothermia; Hypothermia - metabolism; Iodoacetate; Lactic Acid - metabolism; Male; Myocardial Reperfusion - methods; Myocardium - metabolism; Oxidation-Reduction; Palmitate metabolism; Perfusion - methods; Phosphocreatine - metabolism; Pyruvate; Rats; Rats, Sprague-Dawley
• ISSN: 0022-2828; 1095-8584
• DOI: 10.1006/jmcc.1996.0296

In the present study we examined the impact of glycolysis and glucose oxidation on myocardial calcium control and mechanical function, of fatty acid-perfused rat hearts subjected to hypothermia and rewarming. One group (control) was given glucose (11.1 mm) and palmitate (1.2 mM) as energy substrates. In a second group glycolysis was inhibited by iodoacetate (IAA, 100μm) and replacement of glucose with pyruvate (5 mM), whereas in the third group glucose oxidation was stimulated by administration of dichloroacetate (DCA, 1 mM) and insulin (500μU/ml). All groups showed a rise in myocardial calcium ([Ca]total) in response to hypothermia (10°C). However, [Ca]totalwas significantly lower both in IAA- and DCA-treated hearts, as compared to controls (2.20±0.22 and 2.94±0.20v3.83±0.29 nmol/mg dry wt.,P