|
|
||||||||
Departments of 1 Radiology and 2 Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02129
Augmented pyruvate oxidation via pharmacological stimulation of pyruvate dehydrogenase (PDH) during reperfusion has been related to improved recovery of postischemic hearts independent of glycolytic activity. This study examined recovery of postischemic rabbit hearts during activation of PDH with dichloroacetate (DCA) in the presence of lactate, as a source of pyruvate, to determine the response to substrate-dependent changes in cytosolic redox state. After 10 min of ischemia, isolated hearts were reperfused with either 2.5 mM or 0.5 mM pyruvate (Pyr) or 2.5 mM lactate (Lac), with or without 5 mM DCA. 13C-enriched substrates allowed NMR assessment of metabolic perturbations. During normal perfusion, Pyr and Lac supported similar mechanical work. Increasing Pyr oxidation restored postischemic rate-pressure product to 82 ± 4 and 88 ± 6% of preischemic values during reperfusion with 2.5 and 0.5 mM Pyr, respectively, vs. 61 ± 6 and 45 ± 14% for untreated 2.5 and 0.5 mM Pyr, respectively (P < 0.05). In contrast, increasing Lac oxidation did not benefit recovery of RPP in untreated (44 ± 7%) vs. DCA-treated 36 ± 4% hearts. Thus the benefit of PDH activation for contractile recovery of postischemic hearts is mediated by the source of pyruvate, which also influences cytosolic redox state.
reperfusion; lactate; nuclear magnetic resonance spectroscopy; heart; metabolism
This article has been cited by other articles:
![]() |
J. M. O'Donnell, R. K. Kudej, K. F. LaNoue, S. F. Vatner, and E. D. Lewandowski Limited transfer of cytosolic NADH into mitochondria at high cardiac workload Am J Physiol Heart Circ Physiol, June 1, 2004; 286(6): H2237 - H2242. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. A. Carvalho, P. Zhao, C. B. Wiegers, F. M. H. Jeffrey, C. R. Malloy, and A. D. Sherry TCA cycle kinetics in the rat heart by analysis of 13C isotopomers using indirect 1H[13C] detection Am J Physiol Heart Circ Physiol, September 1, 2001; 281(3): H1413 - H1421. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. G. Van Emous, C. L. A. M. Vleggeert-Lankamp, M. G. J. Nederhoff, T. J. C. Ruigrok, and C. J. A. Van Echteld Postischemic Na+-K+-ATPase reactivation is delayed in the absence of glycolytic ATP in isolated rat hearts Am J Physiol Heart Circ Physiol, May 1, 2001; 280(5): H2189 - H2195. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. L. Griffin, L. T. White, and E. D. Lewandowski Substrate-dependent proton load and recovery of stunned hearts during pyruvate dehydrogenase stimulation Am J Physiol Heart Circ Physiol, July 1, 2000; 279(1): H361 - H367. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. D. Lewandowski Metabolic Mechanisms Associated With Antianginal Therapy Circ. Res., March 17, 2000; 86(5): 487 - 489. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |