Service de Chirurgie Cardiovasculaire, Pôle de Cardiologie, Hôpitaux Universitaires, CHRU de Strasbourg, Strasbourg, France.
J Vasc Surg. 2012 Sep;56(3):774-82.e1. doi: 10.1016/j.jvs.2012.01.079. Epub 2012 Jul 15.
Muscular injuries contribute to perioperative and long-term morbidity after vascular surgery in humans. We determined whether local and remote ischemic postconditioning might similarly decrease muscle mitochondrial dysfunction through reduced oxidative stress.
Eighteen male Black-6 mice were divided in three groups: (1) sham mice had no ischemia (sham), (2) ischemia-reperfusion (IR) mice underwent 2-hour tourniquet-induced ischemia on both hind limbs, followed by 2-hour reperfusion, and (3) postconditioning (PoC) mice underwent four bouts of 30-second reperfusion and 30-second ischemia at the onset of reperfusion on the right limb; thus, the right limb underwent local PoC and left limb underwent remote PoC (rPoC). Maximal oxidative capacity (V(max)) of the gastrocnemius muscle mitochondrial respiratory chain was measured. Oxidative stress was evaluated by dihydroethidium staining. Expressions of genes involved in antioxidant defense (superoxide dismutase [SOD1], SOD2, glutathione peroxidase [GPx]), apoptosis (Bax, BclII), and inflammation (interleukin-6) were determined by quantitative real-time polymerase chain reaction. Muscle inflammation was determined using immunohistochemistry.
IR reduced V(max) (8.5 ± 2.2 vs 10.2 ± 1.8 μmol O(2)/min/g dry weight; P = .034), and increased dihydroethidium staining (134.8%; P = .039). IR decreased GPx expression (-47.9%; P = .048) and increased the proapoptotic marker Bax (255.5%; P = .020). Local PoC and rPoC further increased these deleterious effects. PoC decreased V(max) to 4.4 ± 1.4 μmol O(2)/min/g dry weight (sham vs PoC, -56.9% [P < .001]; IR vs PoC, -48.2% [P < .001]). rPoC similarly reduced V(max) to 5.1 ± 1.9 μmol O(2)/min/g dry weight (sham vs PoC, -50.0% [P < .001]; IR vs PoC, -40.0% [P = .001]). Dihydroethidium staining was further increased by PoC (207.2%; P = .002) and rPoC (305.4%; P < .001) compared with sham and was associated with macrophage infiltration. Local PoC increased SOD1, SOD2, and the antiapoptotic Bcl-2, and rPoC increased Bax (391.6%; P < .001) and the Bax/BclII ratio (621.7%; P < .001).
Local and remote ischemic postconditioning further increased injury by enhancing mitochondrial dysfunction, oxidative stress production, and inflammation. Caution should be applied when considering ischemic postconditioning in vascular surgery.
肌肉损伤是导致血管手术后围手术期和长期发病率增加的原因之一。本研究旨在确定局部和远程缺血后处理是否可以通过减少氧化应激来同样减轻肌肉线粒体功能障碍。
将 18 只雄性黑 6 小鼠分为三组：（1）假手术组（sham）未进行缺血处理；（2）缺血再灌注组（IR）在双侧后肢上应用止血带进行 2 小时缺血，随后进行 2 小时再灌注；（3）后处理组（PoC）在再灌注开始时对右侧肢体进行 4 次 30 秒的再灌注和 30 秒的缺血，从而对右侧肢体进行局部后处理（PoC），对左侧肢体进行远程后处理（rPoC）。测量比目鱼肌线粒体呼吸链的最大氧化能力（V(max)）。通过二氢乙啶染色评估氧化应激。通过定量实时聚合酶链反应（PCR）测定抗氧化防御（超氧化物歧化酶[SOD1]、SOD2、谷胱甘肽过氧化物酶[GPx]）、凋亡（Bax、BclII）和炎症（白细胞介素-6）相关基因的表达。使用免疫组织化学检测肌肉炎症。
IR 降低了 V(max)（8.5 ± 2.2 比 10.2 ± 1.8 μmol O(2)/min/g 干重；P =.034），并增加了二氢乙啶染色（134.8%；P =.039）。IR 降低了 GPx 表达（-47.9%；P =.048）并增加了促凋亡标志物 Bax（255.5%；P =.020）。局部后处理和远程后处理进一步增加了这些有害影响。PoC 将 V(max)降低至 4.4 ± 1.4 μmol O(2)/min/g 干重（sham 与 PoC 相比，-56.9%[P <.001]；IR 与 PoC 相比，-48.2%[P <.001]）。rPoC 同样将 V(max)降低至 5.1 ± 1.9 μmol O(2)/min/g 干重（sham 与 PoC 相比，-50.0%[P <.001]；IR 与 PoC 相比，-40.0%[P =.001]）。与 sham 组相比，PoC（207.2%；P =.002）和 rPoC（305.4%；P <.001）进一步增加了二氢乙啶染色，与巨噬细胞浸润有关。局部后处理增加了 SOD1、SOD2 和抗凋亡 Bcl-2，而远程后处理增加了 Bax（391.6%；P <.001）和 Bax/BclII 比值（621.7%；P <.001）。
局部和远程缺血后处理通过增强线粒体功能障碍、氧化应激产生和炎症反应进一步加重了损伤。在血管手术中考虑缺血后处理时应谨慎。
