Activation of p38 MAPK and increased glucose transport in chronic hibernating swine myocardium
1 Division of Cardiology, Veterans Affairs Medical Center, and 2 Division of Cardiology, University of Minnesota, Minneapolis, Minnesota 55417 Submitted 12 December 2003 ; accepted in final form 23 April 2004 In preconditioned myocardium, activation of the mitogen-activated protein kinase (MAPK) p38...
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Published in | American journal of physiology. Heart and circulatory physiology Vol. 287; no. 3; pp. H1328 - H1334 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.09.2004
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Subjects | |
Online Access | Get full text |
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Summary: | 1 Division of Cardiology, Veterans Affairs Medical Center, and 2 Division of Cardiology, University of Minnesota, Minneapolis, Minnesota 55417
Submitted 12 December 2003
; accepted in final form 23 April 2004
In preconditioned myocardium, activation of the mitogen-activated protein kinase (MAPK) p38 leads to increased glucose uptake via enhanced GLUT-4 translocation. Glucose uptake is also increased in chronic hibernating myocardium, but the role of p38 MAPK and GLUT-4 translocation has not been studied. Nine swine underwent instrumentation of the proximal left anterior descending coronary artery (LAD) with a small, external constrictor. At 3 mo after instrumentation, myocardial glucose uptake by PET imaging was higher in the LAD than in the remote region under basal, fasted conditions (0.08 ± 0.02 vs. 0.04 ± 0.01 µmol·min 1 ·g 1 , P < 0.05). Compared with the remote region, the LAD region demonstrated increased membrane-bound GLUT-4 relative to total content (61 ± 04 vs. 45 ± 06%, P < 0.05), higher glycogen (28.37 ± 4.41 vs. 19.26 ± 1.87 mg/g wet wt, P < 0.05), and increased inducible nitric oxide synthase (NOS) activity (1.43 ± 0.34 vs. 0.51 ± 0.21 activity/mg protein, P < 0.05). p38 MAPK was 47 ± 14% higher in the LAD than in the remote region ( P < 0.05) and correlated well with the absolute degree of GLUT-4 membrane-bound translocation ( r = 0.81, P < 0.01), relative increase in glycogen ( r = 0.70, P < 0.05), and total NOS activity ( r = 0.68, P < 0.05). In chronic hibernating myocardial tissue, p38 MAPK activation is increased under basal fasted conditions and correlates well with the increased degree of GLUT-4 translocation, glycogen accumulation, and NOS activity. As in preconditioned myocardium, activation of p38 MAPK may play an important role in the metabolic adaptations that characterize chronic hibernating myocardium.
GLUT-4; glucose uptake; preconditioned myocardium; inducible nitric oxide synthase
Address for reprint requests and other correspondence: E. O. McFalls, Cardiology (111C), VA Medical Center, 1 Veterans Dr., Minneapolis, MN 55417 (E-mail: mcfal001{at}tc.umn.edu ). |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0363-6135 1522-1539 |
DOI: | 10.1152/ajpheart.01188.2003 |