Upregulation of eNOS and unchanged energy metabolism in increased susceptibility of the aging type 2 diabetic GK rat heart to ischemic injury

被引：39

作者：

Desrois, Martine ^{[1
]}

Clarke, Kieran ^{[4
]}

Lan, Carole ^{[1
]}

Dalmasso, Christiane ^{[1
]}

Cole, Mark ^{[4
]}

Portha, Bernard ^{[2
,3
]}

Cozzone, Patrick J. ^{[1
]}

Bernard, Monique ^{[1
]}

机构：

[1] Univ Mediterranee, Ctr Resonance Magnet Biol & Med, CNRS, Fac Med,UMR 6612, F-13385 Marseille 05, France

[2] Univ Paris Diderot, Lab Biol & Pathol Pancreas Endocrine, Unite Biol Fonct & Adapt, Equipe 1, Paris, France

[3] CNRS, Equipe Accueil Convent, Paris, France

[4] Univ Oxford, Univ Lab Physiol, Oxford, England

来源：

AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY | 2010年 / 299卷 / 05期

关键词：

type; 2; diabetes; cardiac ischemia-reperfusion; Goto-Kakizaki rats; nitric oxide; energy metabolism; endothelial nitric oxide synthase; CORONARY FLOW RESERVE; LONG-TERM ISCHEMIA; NITRIC-OXIDE; INSULIN-RESISTANCE; CARDIAC-FUNCTION; L-ARGININE; MITOCHONDRIAL DYSFUNCTION; ENDOTHELIAL DYSFUNCTION; ADRENERGIC-STIMULATION; DIASTOLIC DYSFUNCTION;

D O I：

10.1152/ajpheart.00998.2009

中图分类号：

R5 [内科学];

学科分类号：

100201 [内科学];

摘要：

Desrois M, Clarke K, Lan C, Dalmasso C, Cole M, Portha B, Cozzone PJ, Bernard M. Upregulation of eNOS and unchanged energy metabolism in increased susceptibility of the aging type 2 diabetic GK rat heart to ischemic injury. Am J Physiol Heart Circ Physiol 299: H1679-H1686, 2010. First published August 20, 2010; doi:10.1152/ajpheart.00998.2009.-We investigated the tolerance of the insulin-resistant diabetic heart to ischemic injury in the male Goto-Kakizaki (GK) rat, a model of type 2 diabetes. Changes in energy metabolism, nitric oxide (NO) pathway, and cardiac function were assessed in the presence of physiological substrates. Age-matched control Wistar (n = 19) and GK (n = 18) isolated rat hearts were perfused with 0.4 mM palmitate, 3% albumin, 11 mM glucose, 3 U/l insulin, 0.2 mM pyruvate, and 0.8 mM lactate for 24 min before switching to 1.2 mM palmitate (11 rats/group) during 32 min low-flow (0.5 ml.min(-1).g wet wt(-1)) ischemia. Next, flow was restored with 0.4 mM palmitate buffer for 32 min. A subset of hearts from each group (n = 8 for control and n = 7 for GK groups) were freeze-clamped for determining baseline values after the initial perfusion of 24 min. ATP, phosphocreatine (PCr), and intracellular pH (pH(i)) were followed using P-31 magnetic resonance spectroscopy with simultaneous measurement of contractile function. The NO pathway was determined by nitric oxide synthase (NOS) isoform expression and total nitrate concentration (NOx) in hearts. We found that coronary flow was 26% lower (P < 0.05) during baseline conditions and 61% lower (P < 0.05) during reperfusion in GK vs. control rat hearts. Rate pressure product was lower during reperfusion in GK vs. control rat hearts (P < 0.05). ATP, PCr, and pHi during ischemia-reperfusion were similar in both groups. Endothelial NOS expression was increased in GK rat hearts during baseline conditions (P < 0.05). NOx was increased during baseline conditions (P < 0.05) and after reperfusion (P < 0.05) in GK rat hearts. We report increased susceptibility of type 2 diabetic GK rat heart to ischemic injury that is not associated with impaired energy metabolism. Reduced coronary flow, upregulation of eNOS expression, and increased total NOx levels confirm NO pathway modifications in this model, presumably related to increased oxidative stress. Modifications in the NO pathway may play a major role in ischemia-reperfusion injury of the type 2 diabetic GK rat heart.

引用

页码：H1679 / H1686

页数：8

共 74 条

[1]

Age-dependent changes in metabolism, contractile function, and ischemic sensitivity in hearts from db/db mice [J].