Mitochondrial function during ischemic preconditioning
Autor: | Andriy M. Babsky, Koki Niibori, Mary Osbakken, Natalia M. Doliba, Juan A. Crestanello, Glenn J.R. Whitman, Nicolai M. Doliba |
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Rok vydání: | 2002 |
Předmět: |
Male
medicine.medical_specialty Ventricular rate Ischemia Myocardial Reperfusion Injury Oxidative phosphorylation Mitochondria Heart Rats Sprague-Dawley Adenosine Triphosphate Oxygen Consumption Katp channels Internal medicine parasitic diseases medicine Animals Respiratory function cardiovascular diseases business.industry medicine.disease Rats Surgery Ischemic Preconditioning Myocardial Cardiology Ischemic preconditioning Calcium Respiratory control business Reperfusion injury |
Zdroj: | Surgery. 131:172-178 |
ISSN: | 0039-6060 |
DOI: | 10.1067/msy.2002.119490 |
Popis: | Background. Ischemic preconditioning (IPC) protects the myocardium from ischemia reperfusion injury. The effect of IPC on the mitochondria is not well known. However, one of the mechanisms postulated in IPC (the opening of the mitochondrial K(ATP) channels) is likely to result in changes in mitochondrial function. Therefore, the purpose of this study was to determine the effect of IPC on mitochondrial function during ischemia reperfusion. Methods. Isolated rat hearts (n = 6/group) were subjected to (1) 30 minutes of equilibration, 25 minutes of ischemia, and 30 minutes of reperfusion (RP) (control group) or (2) 10 minutes of equilibration, two-5 minute episodes of IPC (each followed by 5 minutes of re-equilibration), 25 minutes of ischemia, and 30 minutes of RP (IPC group). Left ventricular rate pressure product (RPP) was measured. At end-equilibration (end-EQ) and at end-reperfusion (end-RP) mitochondria were isolated. Mitochondrial respiratory function (state 2, 3, and 4), respiratory control index (RCI), rate of oxidative phosphorylation (ADP/Delta t), and ADP:O ratio were measured by polarography with the use of NADH- or FADH-dependent substrates. Results. IPC improved recovery of RPP at end-RP (72% +/- 5% in IPC vs 30% +/- 4% in control, P.05). Ischemia reperfusion (IR) decreased state 3, ADP/Delta t, and RCI in both groups compared with end-EQ. IPC improved state 3 (47 +/- 3 in IPC vs 37 +/- 2 ng-atoms O/min/mg protein in control), ADP/Delta t (17 +/- 1 in IPC vs 13 +/- 1 nmol/s/mg protein in control), and RCI (3.7 +/- 0.1 in IPC vs 2.1 +/- 0.2 in control) at end-RP compared with control with the use of NADH-dependent substrate (P.05 vs control). IPC also improved state 3 (85 +/- 6 in IPC vs 71 +/- 4 ng-atoms O/min/mg protein in control), ADP/Delta t (18 +/- 2 in IPC vs 12 +/- 1 nmol/s/mg protein in control), RCI (2 +/- 0.1 in IPC vs 1.5 +/- 0.1 in control), and ADP:O ratios (1.4 +/- 0.04 in IPC vs 1.7 +/- 0.09 in control) at end-RP compared with control with the use of FADH-dependent substrate (P.05 vs control). Conclusions. The cardioprotective effects of IPC can be attributed at least in part to the preservation of mitochondrial function during reperfusion. |
Databáze: | OpenAIRE |
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