Effects of Preconditioning and Post Conditioning Statin Treatment on Skeletal Muscle in a Murine Model of Critical Limb Ischemia

Abstract

Introduction: Statins are widely used in the prevention of cardiovascular events, but may cause deleterious effects especially muscle pain. We wanted to investigate the effect of statins on mitochondrial skeletal muscle system in our murine model of critical limb ischemia, depending on whether the treatment is initiated before or after the onset of critical ischemia. Methods: 30 Swiss mice, 8 weeks old, divided into 3 groups: 1 control group (n = 10), one preconditioning group treated with statins 30 days before ischemia until sacrifice (n = 10), and one post-conditioning group treated with statins 6 days after ischemia until sacrifice (n = 10). Operating protocol: ligature of the right femoral artery (Day 0), followed by ligature of the right iliac artery (Day 4). The left lower limb was considered as control. Gastrocnemius muscles were analyzed at sacrifice (Day 30): mitochondrial respiration and production of free radicals in the control limb (CL) and ischemic limb (IL) were examined in the 3 groups. Results: Analysis of control group muscles showed (IL vs CL):•An impairment of mitochondrial respiratory chain characterized by a decrease in the maximum rate of oxygen consumption (Vmax) by mitochondria (reflection of ATP production): 7.11 ± 1.14 vs. 9.86 ± μmol02/min/g 0.86 (p < 0.001).•An increased production of free radicals: 0.105 ± 0.023 vs. 0.073 ± 0.022 μM/min/mg (p < 0.001). In the preconditioning group, mitochondrial respiration is restored in IL (Vmax = 8.85 ± 2.07 vs. 9.08 ± 1.89 μmol02/min/g), and production of free radicals is reduced (0.084 ± 0.018 vs. 0.082 ± 0.027 μM/min/mg). There is no difference between IL and CL. In the post-conditioning group, there is a significant alteration, both in IL and CL, with impaired mitochondrial respiration (Vmax = 5.03 ± 1.14 vs. 6.78 ± 1.29 μmol02/min/g) and increased production of free radicals (0.161 ± 0.077 vs. 0.092 ± 0.052 μM/min/mg). Conclusion: Statins have protective effects on skeletal critical ischemic muscle in primary prevention. They have deleterious effects in secondary prevention, by alteration of the mitochondrial respiratory function and by increased production of free radicals.