Postconditioning for salvage of ischemic skeletal muscle from reperfusion injury: efficacy and mechanism (original) (raw)
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Journal of Applied Physiology, 2006
Ischemia-reperfusion (I/R) injury causes skeletal muscle infarction and ischemic preconditioning (IPC) augments ischemic tolerance in animal models. To date, this has not been demonstrated in human skeletal muscle. This study aimed to develop an in vitro model to investigate the efficacy of simulated IPC in human skeletal muscle. Human skeletal muscle strips were equilibrated in oxygenated Krebs-Henseleit-HEPES buffer (37°C). Aerobic and reperfusion phases were simulated by normoxic incubation and reoxygenation, respectively. Ischemia was simulated by hypoxic incubation. Energy store, cell viability, and cellular injury were assessed using ATP, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT), and lactate dehydrogenase (LDH) assays, respectively. Morphological integrity was assessed using electron microscopy. Studies were designed to test stability of the preparation ( n = 5–11) under normoxic incubation over 24 h; the effect of 1, 2, 3, 4, or 6 h hypoxia foll...
Acta Cirurgica Brasileira, 2013
To investigate the protective effects of ischemic pre and postconditioning, as well as the association of both methods, in skeletal muscle injury produced by ischemia and reperfusion in rats. METHODS: An experimental study was designed using 40 Wistar rats divided in four groups (n=10): Control-rats submitted to ischemia for 240 minutes (min) and reperfusion for 60 min; Ischemic preconditioning (Pre)-animals submitted to three cycles of clamping and releasing the aorta for five min before being submitted to the ischemia/reperfusion procedure; Ischemic postconditioning (Post)-rats submitted to three cycles of clamping and releasing the aorta for one min after the 240-minute ischemic phase; Ischemic pre and postconditioning (Pre-post)-animals submitted to the same procedures of Pre and Post groups. Skeletal muscle injury was evaluated by measuring serum levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine phosphokinase (CPK); and muscular levels of malondialdehyde (MDA) and glycogen. RESULTS: AST levels were significantly higher in Pre and Pre-post groups (P<.01). There were no differences in LDH and CPK levels. Muscular MDA levels were similar. Glycogen levels were significantly higher in Pre and Pre-post groups (P<.01). CONCLUSIONS: Both preconditioning and its association with postconditioning had a protective effect by avoiding glycogen depletion in skeletal muscle in rats submitted to ischemia and reperfusion. Association of pre and postconditioning did not show advantage compared to preconditioning alone. Postconditioning alone did not show protective effect.
AJP: Regulatory, Integrative and Comparative Physiology, 2005
We have previously demonstrated that remote ischemic preconditioning (IPC) by instigation of 3 cycles of 10 min occlusion/reperfusion in a hind limb of the pig elicits an early phase of infarct protection in local and distant skeletal muscles subjected to 4h of ischemia immediately after remote IPC. The aim of this project was to test our hypothesis that hind limb remote IPC also induces a late phase of infarct protection in skeletal muscle, and K ATP channels play a pivotal role in the trigger and mediator mechanisms. We observed that pig bilateral latissimus dorsi (LD) muscle flaps sustained 46 ± 2% infarction when subjected to 4h of ischemia/48h of reperfusion. The late phase of infarct protection appeared at 24h and lasted up to 72h after hind limb remote IPC.
Pharmacologic intervention in ischemia-induced reperfusion injury in the skeletal muscle
Microsurgery, 1993
muscle. Special emphasis is placed on the recent observation of the acute ischemic preconditioning phenomenon for prevention of I/R injury in skeletal muscle. Finally, the mechanism of ischemic preconditioning and its clinical applications for augmentation of skeletal muscle tolerance to prolonged ischemic insult are discussed. o im wiiey-~iss, inc.
Annals of Vascular Surgery, 2017
Purpose: analyze the effects of ischemic postconditioning on skeletal muscle injury and apoptosis produced by partial ischemia and reperfusion in rats. Materials and Methods: An experimental study was designed using 70 Wistar rats divided in three groups: Sham; Control-submitted to ischemia and reperfusion; Postconditioning-submitted to ischemia and reperfusion with ischemic postconditioning. Subgroups (n=10) were divided by duration of ischemia (four, five or six hours). A partial ischemia model using aortic clamping was used. The postconditioning protocol consisted of three cycles of clamping the aorta for one minute and releasing for another minute. Skeletal muscle injury was evaluated by measuring serum levels of of releasing cytoplasmic enzymes: aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and total creatine phosphokinase (CPK). Lipid peroxidation was evaluated by muscular levels of malondialdehyde (MDA). Energetic cell storage was evaluated by muscular glycogen levels. Apoptosis was evaluated analyzing the expression of caspase 3 and protein B-cell lymphoma 2 (Bcl-2) by immunohistochemistry. Results: AST levels in Sham group were 109.80 Units/L, in Control subgroups were: 4h 200.60 Units/L / 5h 392.30 Units/L / 6h 118.82 Units/L, whereas in Postconditioning subgroups were: 4h 316.10 Units/L / 5h 268.40 Units/L / 6h 267.00 Units/L. There was a two to threefold-increase in Control and Postconditioning groups compared with Sham group (P = .003) There was no difference between groups with the same ischemic injury time. LDH, CPK and MDA levels were similar in Sham, Control and Postconditioning groups.
American Journal of Physiology-Heart and Circulatory Physiology, 2004
We previously demonstrated in the pig that instigation of three cycles of 10 min of occlusion and reperfusion in a hindlimb by tourniquet application (∼300 mmHg) elicited protection against ischemia-reperfusion injury (infarction) in multiple distant skeletal muscles subsequently subjected to 4 h of ischemia and 48 h of reperfusion, but the mechanism was not studied. The aim of this project was to test our hypothesis that mitochondrial ATP-sensitive potassium (KATP) (mKATP) channels play a central role in the trigger and mediator mechanisms of hindlimb remote ischemic preconditioning (IPC) of skeletal muscle against infarction in the pig. We observed in the pig that hindlimb remote IPC reduced the infarct size of latissimus dorsi (LD) muscle flaps (8 × 13 cm) from 45 ± 2% to 22 ± 3% ( n = 10; P < 0.05). The nonselective KATPchannel inhibitor glibenclamide (0.3 mg/kg) or the selective mKATPchannel inhibitor 5-hydroxydecanoate (5-HD, 5 mg/kg), but not the selective sarcolemmal KATP...
Impaired Skeletal Muscle Repair after Ischemia-Reperfusion Injury in Mice
Journal of Biomedicine and Biotechnology, 2010
Ischemia/reperfusion (IR) injury can induce skeletal muscle fibre death and subsequent regeneration. By 14 days, absolute and specific maximal forces and fatigue resistance in ischemic/reperfused soleus muscles were still reduced (−89%, −81%, and −75%, resp.) as compared to control muscles (P<.05). The decrease of these parameters in ischemic/reperfused muscle was much greater than that of myotoxic injured muscles (−12%, −11%, and −19%;P<.05). In addition, at 14 days ischemic/reperfused muscle structure was still abnormal, showing small muscle fibres expressing neonatal myosin heavy chain and large necrotic muscle fibres that were not observed in myotoxin treated muscles. By 56 days, in contrast to myotoxin treated muscles, specific maximal force and muscle weight of the ischemic/reperfused muscles did not fully recover (P<.05). This differential recovery between ischemic/reperfused and myotoxin treated muscles was not related to the differences in the initial cell death, l...
Protective mechanisms during ischemic tolerance in skeletal muscle
Free Radical Biology and Medicine, 2004
The purpose of this study was to test specific mechanisms of protection afforded the rat extensor digitorum longus (EDL) muscle during ischemic tolerance. Two days following five cycles of 10 min ischemia and 10 min reperfusion, heme oxygenase (HO) and calcium-dependent nitric oxide synthase (cNOS) activities were increased 2-and 2.5-fold ( p < .05), respectively. Interestingly, calcium-independent NOS (iNOS) activity was completely downregulated ( p < .05). The levels of superoxide dismutase (SOD) and catalase were increased 2-fold ( p < .05), while glutathione peroxidase activity remained unchanged from non-preconditioned controls. Using intravital microscopy combined with chromium mesoporphyrin (CrMP), a selective HO inhibitor, and L-NAME, a NOS inhibitor, the roles of HO and cNOS were evaluated. Ischemic tolerance in the EDL muscle, 48 h after the preconditioning stimulus, was characterized by complete protection from both microvascular perfusion deficits and tissue injury after a 2-h period of ischemia. Removal of NOS activity completely removed the benefit afforded microvascular perfusion, while inhibition of HO activity prevented the parenchymal protection. These data suggest that ischemic tolerance within skeletal muscle is associated with the upregulation of specific cytoprotective proteins and that the benefits afforded by cNOS and HO activity are spatially discrete to the microvasculature and parenchyma, respectively. D
Mechanisms of Ischemic Preconditioning in Skeletal Muscle
Journal of Surgical Research, 2000
Background. Ischemic preconditioning (IP) (one or more cycles each consisting of a short period of ischemia and a short period of reperfusion, before the sustained ischemia) reduces ischemia-related organ damage in heart and skeletal muscle but the underlying mechanisms are not clear. This study was intended to assess the possible involvement of K ATP channels and of adenosine receptors in IP of skeletal muscle in a rat model of skeletal muscle ischemia. Materials and methods. Groups of 8-15 rats were given the following in vivo treatments: ischemiareperfusion (I-R: 2.5 h tourniquet-induced ischemia of the right hindlimb, then 2 h reperfusion); IP (three cycles of 5 min ischemia, then 5 min reperfusion) be