Contribution of malonyl-CoA decarboxylase to the high fatty acid oxidation rates seen in the diabetic heart

• Published in: American journal of physiology. Heart and circulatory physiology 2000-04, Vol.278 (4), p.H1196-H1204
• Main Authors: Sakamoto, Jun, Barr, Rick L, Kavanagh, Katherine M, Lopaschuk, Gary D
• Format: Article
• Language: English
• Subjects: Acetyl-CoA Carboxylase - metabolism; AMP-Activated Protein Kinases; Animals; Blood Glucose - metabolism; Body Weight; Carboxy-Lyases - metabolism; Carnitine O-Palmitoyltransferase - metabolism; Citric Acid Cycle - drug effects; Citric Acid Cycle - physiology; Diabetes Mellitus, Experimental - enzymology; Enzyme Activation - drug effects; Enzyme Activation - physiology; Fatty Acids - blood; Fatty Acids - pharmacology; Glucose - pharmacology; In Vitro Techniques; Male; Multienzyme Complexes - metabolism; Myocardium - enzymology; Oxidation-Reduction; Palmitic Acid - metabolism; Protein-Serine-Threonine Kinases - metabolism; Rats; Rats, Sprague-Dawley
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.2000.278.4.h1196

Cardiovascular Research Group, University of Alberta, Edmonton, Alberta, Canada T6G 2S2 Myocardial glucose oxidation is markedly reduced in the uncontrolled diabetic. We determined whether this was due to direct biochemical changes in the heart or whether this was due to altered circulating levels of insulin and substrates that can be seen in the diabetic. Isolated working hearts from control or diabetic rats (streptozotocin, 55 mg/kg iv administered 6 wk before study) were aerobically perfused with either 5 mM [ 14 C]glucose and 0.4 mM [ 3 H]palmitate (low-fat/low-glucose buffer) or 20 mM [ 14 C]glucose and 1.2 mM [ 3 H]palmitate (high-fat/high-glucose buffer) ±100 µU/ml insulin. The presence of insulin increased glucose oxidation in control hearts perfused with low-fat/low-glucose buffer from 553 ± 85   to 1,150 ± 147 nmol · g dry wt 1 · min 1 ( P