Differences in intrinsic aerobic capacity alters sensitivity to ischemia-reperfusion injury but not cardioprotective capacity by ischemic preconditioning in rats

TY - JOUR

T1 - Differences in intrinsic aerobic capacity alters sensitivity to ischemia-reperfusion injury but not cardioprotective capacity by ischemic preconditioning in rats

AU - Hjortbak, Marie Vognstoft

AU - Grønnebæk, Thomas Skjærlund

AU - Jespersen, Nichlas Riise

AU - Lassen, Thomas Ravn

AU - Seefeldt, Jacob Marthinsen

AU - Tonnesen, Pernille Tilma

AU - Jensen, Rebekka Vibjerg

AU - Koch, Lauren Gerard

AU - Britton, Steven L

AU - Pedersen, Michael

AU - Jessen, Niels

AU - Bøtker, Hans Erik

PY - 2020/10

Y1 - 2020/10

N2 - INTRODUCTION: Aerobic capacity is a strong predictor of cardiovascular mortality. Whether aerobic capacity influences myocardial ischemia and reperfusion (IR) injury is unknown.PURPOSE: To investigate the impact of intrinsic differences in aerobic capacity and the cardioprotective potential on IR injury.METHODS: We studied hearts from rats developed by selective breeding for high (HCR) or low (LCR) capacity for treadmill running. The rats were randomized to: (1) control, (2) local ischemic preconditioning (IPC) or (3) remote ischemic preconditioning (RIC) followed by 30 minutes of ischemia and 120 minutes of reperfusion in an isolated perfused heart model. The primary endpoint was infarct size. Secondary endpoints included uptake of labelled glucose, content of selected mitochondrial proteins in skeletal and cardiac muscle, and activation of AMP-activated kinase (AMPK).RESULTS: At baseline, running distance was 203±7 m in LCR vs 1905±51 m in HCR rats (p<0.01). Infarct size was significantly lower in LCR than in HCR controls (49±5% vs 68±5%, p = 0.04). IPC reduced infarct size by 47% in LCR (p<0.01) and by 31% in HCR rats (p = 0.01). RIC did not modulate infarct size (LCR: 52±5, p>0.99; HCR: 69±6%, p>0.99, respectively). Phosphorylaion of AMPK did not differ between LCR and HCR controls. IPC did not modulate cardiac phosphorylation of AMPK. Glucose uptake during reperfusion was similar in LCR and HCR rats. IPC increased glucose uptake during reperfusion in LCR animals (p = 0.02). Mitochondrial protein content in skeletal muscle was lower in LCR than in HCR (0.77±0.10 arbitrary units (AU) vs 1.09±0.07 AU, p = 0.02), but not in cardiac muscle.CONCLUSION: Aerobic capacity is associated with altered myocardial sensitivity to IR injury, but the cardioprotective effect of IPC is not. Glucose uptake, AMPK activation immediately prior to ischemia and basal mitochondrial protein content in the heart seem to be of minor importance as underlying mechanisms for the cardioprotective effects.

AB - INTRODUCTION: Aerobic capacity is a strong predictor of cardiovascular mortality. Whether aerobic capacity influences myocardial ischemia and reperfusion (IR) injury is unknown.PURPOSE: To investigate the impact of intrinsic differences in aerobic capacity and the cardioprotective potential on IR injury.METHODS: We studied hearts from rats developed by selective breeding for high (HCR) or low (LCR) capacity for treadmill running. The rats were randomized to: (1) control, (2) local ischemic preconditioning (IPC) or (3) remote ischemic preconditioning (RIC) followed by 30 minutes of ischemia and 120 minutes of reperfusion in an isolated perfused heart model. The primary endpoint was infarct size. Secondary endpoints included uptake of labelled glucose, content of selected mitochondrial proteins in skeletal and cardiac muscle, and activation of AMP-activated kinase (AMPK).RESULTS: At baseline, running distance was 203±7 m in LCR vs 1905±51 m in HCR rats (p<0.01). Infarct size was significantly lower in LCR than in HCR controls (49±5% vs 68±5%, p = 0.04). IPC reduced infarct size by 47% in LCR (p<0.01) and by 31% in HCR rats (p = 0.01). RIC did not modulate infarct size (LCR: 52±5, p>0.99; HCR: 69±6%, p>0.99, respectively). Phosphorylaion of AMPK did not differ between LCR and HCR controls. IPC did not modulate cardiac phosphorylation of AMPK. Glucose uptake during reperfusion was similar in LCR and HCR rats. IPC increased glucose uptake during reperfusion in LCR animals (p = 0.02). Mitochondrial protein content in skeletal muscle was lower in LCR than in HCR (0.77±0.10 arbitrary units (AU) vs 1.09±0.07 AU, p = 0.02), but not in cardiac muscle.CONCLUSION: Aerobic capacity is associated with altered myocardial sensitivity to IR injury, but the cardioprotective effect of IPC is not. Glucose uptake, AMPK activation immediately prior to ischemia and basal mitochondrial protein content in the heart seem to be of minor importance as underlying mechanisms for the cardioprotective effects.

UR - http://www.scopus.com/inward/record.url?scp=85094830353&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0240866

DO - 10.1371/journal.pone.0240866

M3 - Journal article

C2 - 33108389

SN - 1932-6203

VL - 15

JO - PLOS ONE

JF - PLOS ONE

IS - 10

M1 - e0240866

ER -