Muscle injury resulting from ischemia-reperfusion largely aggravates patient prognosis but whether and how muscle phenotype modulates ischemia-reperfusion-induced mitochondrial dysfunction remains to be investigated. We challenged the hypothesis that glycolytic muscles are more prone to ischemia-reperfusion-induced injury than oxidative skeletal muscles. We therefore determined simultaneously the effect of 3 h of ischemia induced by aortic clamping followed by 2 h of reperfusion (IR, n = 11) on both gastrocnemius and soleus muscles, as compared to control animals (C, n = 11). Further, we investigated whether tempol, an antioxidant mimicking superoxide dismutase, might compensate a reduced defense system, likely characterizing glycolytic muscles (IR-Tempol, n = 7). In the glycolytic gastrocnemius muscle, as compared to control, ischemia-reperfusion significantly decreased mitochondrial respiration (−30.28 ± 6.16%, p = 0.003), increased reactive oxygen species production (+79.15 ± 28.72%, p = 0.04), and decreased reduced glutathione (−28.19 ± 6.80%, p = 0.011). Less deleterious effects were observed in the oxidative soleus muscle (−6.44 ± 6.30%, +4.32 ± 16.84%, and −8.07 ± 10.84%, respectively), characterized by enhanced antioxidant defenses (0.63 ± 0.05 in gastrocnemius vs. 1.24 ± 0.08 μmol L−1 g−1 in soleus). Further, when previously treated with tempol, glycolytic muscle was largely protected against the deleterious effects of ischemia-reperfusion. Thus, oxidative skeletal muscles are more protected than glycolytic ones against ischemia-reperfusion, thanks to their antioxidant pool. Such pivotal data support that susceptibility to ischemia-reperfusion-induced injury differs between organs, depending on their metabolic phenotypes. This suggests a need to adapt therapeutic strategies to the specific antioxidant power of the target organ to be protected.
Acute and chronic ischemia induce mitochondrial dysfunction in human skeletal muscles, and improving muscle mitochondrial function improves subjects’ status. Compared with local ischemic preconditioning (IPC), remote IPC (rIPC) appears easier to perform and is safer for the vessel and territory involved in ischemic injury. This study demonstrates that the muscle protection afforded by rIPC is equivalent to that achieved by IPC. Acknowledging that IPC procedures should be specifically adapted to patient characteristics to be successful, our results support a broader use of rIPC in the setting of vascular surgery.
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