Xanthine oxidase and activated neutrophils cause oxidative damage to skeletal muscle after contractile claudication

Abstract

Judge, A. R., and S. L. Dodd. Xanthine oxidase and activated neutrophils cause oxidative damage to skeletal muscle after contractile claudication. Am J Physiol Heart Circ Physiol 286: H252-H256, 2004. First published September 11, 2003 10.1152/ajpheart.00684. 2003.-We previously showed oxidative damage and edema within skeletal muscle after contractile claudication. To investigate the sources of this oxidative damage in the gastrocnemius muscle, we administered allopurinol (Allo, to inhibit xanthine oxidase) and cyclophosphamide (Cyclo, to deplete neutrophils) before inducing contractile claudication in male Sprague Dawley rats. Contractile claudication (ligated stimulated, LS) caused a significant increase in xanthine oxidase activity [sham ligated stimulated (SS) ϭ 2.57 Ϯ 0.07; LS ϭ 3.22 Ϯ 0.07] and neutrophil infiltration (SS ϭ 0.47 Ϯ 0.03; LS ϭ 0.91 Ϯ 0.10) compared with controls (SS), and this was associated with increased lipid peroxidation, protein oxidation, muscle damage, and edema. Pretreatment with Allo attenuated the increase in xanthine oxidase activity and attenuated lipid hydroperoxides (control LS ϭ 12.85 Ϯ 0.50; Allo LS ϭ 9.96 Ϯ 0.71), muscle damage, and neutrophil infiltration (control LS ϭ 0.91 Ϯ 0.10; Allo LS ϭ 0.61 Ϯ 0.07). This latter finding suggests that xanthine oxidasederived oxidants are chemotactic to neutrophils. Pretreatment with Cyclo reduced neutrophil infiltration (control LS ϭ 0.91 Ϯ 0.10; Cyclo LS ϭ 0.55 Ϯ 0.02) and attenuated lipid peroxidation (control LS ϭ 12.85 Ϯ 0.50; Cyclo LS ϭ 6.462 Ϯ 0.62), protein oxidation (control LS ϭ 2.59 Ϯ 0.47; Cyclo LS ϭ 1.77 Ϯ 0.60), muscle damage, and edema. Together, these data indicate that contractile claudication causes an increase in xanthine oxidase activity and neutrophils in muscle and that inhibition of these oxidant sources protects against oxidative stress, muscle damage, and edema. occlusion; free radicals; reactive oxygen species; muscle contraction SEVERAL STUDIES HAVE SHOWN that ischemia-reperfusion (I/R) caused by exercise claudication elevates markers of oxidative damage in the plasma. Hickman et al. (16) exercised claudicant patients for 10 min and found an increase in plasma malondialdehyde levels after exercise, whereas Silvestro et al. (32) showed an increase in thiobarbituric acid-reactive substances, as a marker of lipid peroxidation, after maximal, but not submaximal, exercise in claudicants.Likewise, markers of oxidative damage are also elevated in skeletal muscle after claudication. We recently found (21) an increase in protein oxidation and lipid peroxidation and a reduction in total glutathione levels 1 h after exercise with an animal model of claudication. This was associated with an increase in xanthine oxidase activity and neutrophils-both sources of oxidizing species.To further explore these findings and determine the relative contributions of each pathway, we chose to 1) inhibit xanthine oxidase activity and 2) deplete neutrophils and then measure markers of oxidative damage. Thus the purpose of this study wa...

IκBα degradation is necessary for skeletal muscle atrophy associated with contractile claudication

“…Therefore, although the presence of PAD and/or its associated comorbidities may contribute to the muscle atrophy in PAD patients, our findings, here, suggest that repeated bouts of exercise claudication may also be a major factor in the progression of muscle wasting in PAD patients. These data are in agreement with our previous findings, using the same model, that showed contractile claudication increases markers of oxidative damage in skeletal muscle (24,25,27). Our results are also in conjunction with data from exercising PAD patients demonstrating that exercise increases plasma cytokine and oxidant levels (6,13,18,28,50,51).…”

“…Two days following the ligation or sham surgery, in vivo muscle contractions began using a stimulation protocol previously optimized to cause a significant decrease in force production from limbs in which the femoral artery is ligated, but not in control limbs (24,25,27). The decrease in force production indicates insufficient oxygen delivery to the muscles.…”

“…For these reasons, the model used here has previously been used by our group, and others, to mimic exercise claudication (17,24,25,27). We have previously shown, using this model, that force production from the triceps surae muscle group decreases by ϳ10% in control limbs and ϳ50% in ligated limbs after 15 min of stimulation (24), and by ϳ15% and 70% in control and ligated limbs, respectively, after 30 mins of stimulation (24,25,27). The small decrease in control limbs demonstrates that the stimulation protocol is not intense.…”

Accelerated skeletal muscle recovery after in vivo polyphenol administration

“…Similarly, the increased release of free radicals in the first 24 h after acute stretch-induced skeletal muscle injury [21] causes secondary damage [22]. Oxidative stress in skeletal muscle is increased in various other models such as electrical stimulation during claudication and is ascribed to increased enzymeinitiated oxidant production as well as to neutrophil-derived myeloperoxidase activity [23]. In a model of acute muscle injury in response to a single eccentric contraction, inhibition of the neutrophil oxidative burst and degranulation decreased microscopic damage [24].…”

Oxidative Stress in Muscle Growth and Adaptation to Physical Exercise

“…NADP(H) oxidase activity can be stimulated by calcium-dependent and independent forms of phospholipase A2 in both cytosol and mitochondria [32]. The last notable superoxide-producing enzyme in skeletal muscle is xanthine oxidase [21]. This enzyme catalyzes the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid.…”