Leukocyte activation in ischemia-reperfusion injury of skeletal muscle

Mechanical loading and injury induce human myotubes to release neutrophil chemoattractants

“…Conflicting results have been reported on whether skeletal muscle injured in vivo by mechanical loading or by reperfusion increases ROS production from blood neutrophils in vitro (6,7,37). Whether skeletal muscle cells are the source of primers and/or activators for neutrophil-derived ROS production after mechanical loading and/or injury, however, is unknown.…”

The inflammatory response: friend or enemy for muscle injury?: Figure 1

“…Muscle injury by inflammatory cells has been examined most thoroughly in experimental models of muscle ischaemia followed by reperfusion, in which neutrophils have been clearly shown to promote muscle fibre damage during the reperfusion phase. [18][19][20] It is clear from non-exercise models, in particular ischaemiareperfusion studies, that increased neutrophil adhesiveness to the endothelium is a critical early step in the sequence of events leading to muscle damage. 21 Furthermore, there is very strong evidence that polymorphonuclear leucocytes (particularly neutrophils) and oxygen free radicals are key mediators of ischaemia related tissue injury.…”

Detection of free radicals in ischemic and reperfused canine gracilis muscle flaps by use of spin-trapping electron paramagnetic resonance spectroscopy

“…Therefore, most studies investigating free radical formation in skeletal muscle make use of indirect methods to assess reperfusion injury. Such indirect methods include measurement of vascular permeability, 9,14 muscle xanthine oxidase activity, 11,13 leukocyte activation, 12 and concentrations of degradation products (eg, malondialdehyde as an indicator of lipid peroxidation). [13][14][15] Studies using these indirect methods typically compare an untreated control group with a group treated with a known antioxidant such as allopurinol or superoxide dismutase.…”

“…Compared with other organs, reperfusion injury in skeletal muscle has been the focus of relatively few studies. [8][9][10][11][12][13] Free radicals are difficult to detect in biological systems because of their brief half life. Moreover, free radicals are found in low concentrations in tissues.…”