کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6253653 | 1288407 | 2015 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Association for Academic SurgeryExpression of uncoupling protein-2 remains increased within hibernating myocardium despite successful coronary artery bypass grafting at 4Â wk post-revascularization Association for Academic SurgeryExpression of uncoupling protein-2 remains increased within hibernating myocardium despite successful coronary artery bypass grafting at 4Â wk post-revascularization](/preview/png/6253653.png)
BackgroundWe have previously shown that mitochondrial uncoupling protein-2 (UCP-2) is increased in a swine model of hibernating myocardium (HM). Although UCP-2 reduces oxidant stress, it can promote inefficiency of the electron transport chain. In this study, we tested whether UCP-2 remains increased in revascularized HM (RHM) after coronary artery bypass grafting (CABG).MethodsSeven swine underwent thoracotomy with placement of a constrictor on the left anterior descending artery (LAD). Twelve weeks later, a left internal mammary artery graft was placed on the distal LAD. Four weeks post-CABG, computed tomography angiography documented patent grafts and function. At the terminal study, blood flow to the LAD and remote territories were assessed during high dose dobutamine and mitochondria isolated from both regions for analysis. Comparisons were made to a group of swine with HM who underwent constrictor placement without bypass grafting (n = 4).ResultsDuring dobutamine infusion, RHM demonstrated lower blood flows (2.44 ± 0.23 versus 3.43 ± 0.30 mL/min/g; P < 0.05) and reduced wall thickening (33 ± 9% versus 52 ± 13%; P < 0.05) compared with remote regions. RHM had lower respiratory control indices (3.7 ± 0.3 versus 4.3 ± 0.4; P < 0.05) with persistently increased UCP-2 content.ConclusionsDespite patent grafts, RHM demonstrates a submaximal response to dobutamine infusion and increased mitochondrial UCP-2 expression. These data support the notion that recovery of the mitochondria in RHM is delayed early post-CABG and may contribute to impaired oxygen consumption and contractile reserve during catecholamine challenges.
Journal: Journal of Surgical Research - Volume 193, Issue 1, January 2015, Pages 15-21