| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on December 17, 2005
Revised on May 10, 2006
Accepted on May 19, 2006
From the Cardiovascular Research Group and Departments of Pediatrics and Pharmacology, University of Alberta, Edmonton, Canada.
* To whom correspondence should be addressed. E-mail: gary.lopaschuk{at}ualberta.ca.
The cardioprotective effect of insulin during ischemia-reperfusion has been associated with stimulation of glucose uptake and glycolysis. Although fatty acids and 5'-AMP activated protein kinase (AMPK) are regulators of glucose metabolism, it is unknown what effect insulin has on postischemic function and AMPK activity in the presence of high levels of fatty acid. Isolated ejecting mouse hearts were perfused with Krebs-Henseleit solution containing 5 mmol · L-1 glucose and 0, 0.2, or 1.2 mmol · L-1 palmitate, with or without 100 µU/mL insulin. During aerobic perfusion in the absence of palmitate, insulin stimulated glycolysis by 73% and glucose oxidation by 54%, while inhibiting AMPK activity by 43%. In the presence of 0.2 or 1.2 mmol · L-1 palmitate, insulin stimulated glycolysis by 111% and 105% and glucose oxidation by 72% and 274% but no longer inhibited AMPK activity. During reperfusion of hearts in the absence of palmitate, insulin increased recovery of cardiac power by 47%. This was associated with a 97% increase in glycolysis and a 160% increase in glucose oxidation. However, in the presence of 1.2 mmol · L-1 palmitate, insulin now decreased recovery of cardiac power by 42%. During reperfusion, glucose oxidation was inhibited by high fat, but insulin-stimulated glycolysis remained high, resulting in increased proton production. In the absence of fatty acids, insulin blunted the ischemia-induced activation of AMPK, but this effect was lost in the presence of fatty acids. We demonstrate that the cardioprotective effect of insulin and its ability to inhibit AMPK activity are lost in the presence of high concentrations of fatty acids.
Related Article:
This article has been cited by other articles:
![]() |
J. Suzuki, M. Ueno, M. Uno, Y. Hirose, Y. Zenimaru, S. Takahashi, J.-i. Osuga, S. Ishibashi, M. Takahashi, M. Hirose, et al. Effects of hormone-sensitive lipase disruption on cardiac energy metabolism in response to fasting and refeeding Am J Physiol Endocrinol Metab, November 1, 2009; 297(5): E1115 - E1124. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. D. L. Folmes, C. S. Wagg, M. Shen, A. S. Clanachan, R. Tian, and G. D. Lopaschuk Suppression of 5'-AMP-activated protein kinase activity does not impair recovery of contractile function during reperfusion of ischemic hearts Am J Physiol Heart Circ Physiol, July 1, 2009; 297(1): H313 - H321. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. K. Philp, B. S. Muhlhausler, A. Janovska, G. A. Wittert, J. A. Duffield, and I. C. McMillen Maternal overnutrition suppresses the phosphorylation of 5'-AMP-activated protein kinase in liver, but not skeletal muscle, in the fetal and neonatal sheep Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2008; 295(6): R1982 - R1990. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Bertrand, S. Horman, C. Beauloye, and J.-L. Vanoverschelde Insulin signalling in the heart Cardiovasc Res, July 15, 2008; 79(2): 238 - 248. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. R. Ussher and G. D. Lopaschuk The malonyl CoA axis as a potential target for treating ischaemic heart disease Cardiovasc Res, July 15, 2008; 79(2): 259 - 268. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Gandhi, B. A. Finegan, and A. S. Clanachan Role of glucose metabolism in the recovery of postischemic LV mechanical function: effects of insulin and other metabolic modulators Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2576 - H2586. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Wang, R. V. Donthi, J. Wang, A. J. Lange, L. J. Watson, S. P. Jones, and P. N. Epstein Cardiac phosphatase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase increases glycolysis, hypertrophy, and myocyte resistance to hypoxia Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2889 - H2897. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. F. du Toit, W. Smith, C. Muller, H. Strijdom, B. Stouthammer, A. J. Woodiwiss, G. R. Norton, and A. Lochner Myocardial susceptibility to ischemic-reperfusion injury in a prediabetic model of dietary-induced obesity Am J Physiol Heart Circ Physiol, May 1, 2008; 294(5): H2336 - H2343. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Kaiserova, X.-L. Tang, S. Srivastava, and A. Bhatnagar Role of Nitric Oxide in Regulating Aldose Reductase Activation in the Ischemic Heart J. Biol. Chem., April 4, 2008; 283(14): 9101 - 9112. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. D. Evans and Y. Niu Hypolipidaemic effects of high-dose insulin therapy Br. J. Anaesth., April 1, 2008; 100(4): 429 - 433. [Full Text] [PDF] |
||||
![]() |
L. Zhou, H. Huang, C. L. Yuan, W. Keung, G. D. Lopaschuk, and W. C. Stanley Metabolic response to an acute jump in cardiac workload: effects on malonyl-CoA, mechanical efficiency, and fatty acid oxidation Am J Physiol Heart Circ Physiol, February 1, 2008; 294(2): H954 - H960. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. P.Y. Koonen, R. L. Jacobs, M. Febbraio, M. E. Young, C.-L. M. Soltys, H. Ong, D. E. Vance, and J. R.B. Dyck Increased Hepatic CD36 Expression Contributes to Dyslipidemia Associated With Diet-Induced Obesity Diabetes, December 1, 2007; 56(12): 2863 - 2871. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. D. Folmes, L. A. Witters, M. F. Allard, M. E. Young, and J. R. B. Dyck The AMPK {gamma}1 R70Q mutant regulates multiple metabolic and growth pathways in neonatal cardiac myocytes Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3456 - H3464. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. D. Lopaschuk, C. D.L. Folmes, and W. C. Stanley Cardiac Energy Metabolism in Obesity Circ. Res., August 17, 2007; 101(4): 335 - 347. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Carvajal, E. Zarrinpashneh, O. Szarszoi, F. Joubert, Y. Athea, P. Mateo, B. Gillet, S. Vaulont, B. Viollet, X. Bigard, et al. Dual cardiac contractile effects of the {alpha}2-AMPK deletion in low-flow ischemia and reperfusion Am J Physiol Heart Circ Physiol, June 1, 2007; 292(6): H3136 - H3147. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. D. Hafstad, A. M. Khalid, O.-J. How, T. S. Larsen, and E. Aasum Glucose and insulin improve cardiac efficiency and postischemic functional recovery in perfused hearts from type 2 diabetic (db/db) mice Am J Physiol Endocrinol Metab, May 1, 2007; 292(5): E1288 - E1294. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. D.L. Folmes and G. D. Lopaschuk Role of malonyl-CoA in heart disease and the hypothalamic control of obesity Cardiovasc Res, January 15, 2007; 73(2): 278 - 287. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. H. Opie and H. Selker Letter by Opie and Selker Regarding Article, "Reperfusion Starts in the Ambulance" Circulation, December 12, 2006; 114(24): e640 - e640. [Full Text] [PDF] |
||||
![]() |
R. Tian and J. A. Balschi Interaction of Insulin and AMPK in the Ischemic Heart: Another Chapter in the Book of Metabolic Therapy? Circ. Res., July 7, 2006; 99(1): 3 - 5. [Full Text] [PDF] |
||||
|
Circulation Research Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2006 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |