Polymorphonuclear leucocytes increase reperfusion injury in skeletal muscle.
OBJECTIVE
To study the effect of polymorphonuclear leucocytes (PMNLs) on reperfusion injury in rabbit skeletal muscle and to evaluate the role of oxygen-derived free radicals in PMNL-mediated reperfusion injury.


METHODS
An isolated rabbit limb perfusion model. Amputated hindlimbs were subjected to 4 hours of ischaemia followed by 2 hours of reperfusion with oxygenated Krebs' buffer.


METHODS
Department of experimental surgery.


METHODS
14 rabbits.


METHODS
In group I (n = 8), one limb from each animal was reperfused with PMNL-supplemented buffer while the other limb was reperfused with cell-free buffer (control). In group II (n = 6), SOD and catalase were added to the limb reperfused with PMNL-supplemented buffer while the other limb was reperfused with cell-free buffer without SOD and catalase (control).


METHODS
PMNL accumulation as myeloperoxidase (MPO) activity, muscle necrosis as uptake of [Tc99]methylenediphosphonate (MDP), and oedema as increase in muscle water content (MWC). Electron microscopy was performed for histological demonstration of reperfusion injury.


RESULTS
Addition of PMNLs increased MPO activity (p < 0.05) and MDP uptake (p < 0.05) but did not affect MWC. SOD and catalase treatment of limbs perfused with PMNLs prevented the increase in MPO activity (p < 0.05) and reduced MDP uptake (p < 0.05) and MWC (p < 0.05). PMNLs aggravated histological changes seen after reperfusion.


CONCLUSIONS
Reperfusion injury in skeletal muscle is, at least partially, mediated by PMNLs. Free radical scavengers reduce PMNL-dependent injury and prevent PMNL accumulation suggesting that oxygen-derived free radicals are mediators of PMNL-dependent injury and/or engaged in the interaction between PMNLs and the microvascular endothelium.
Oredsson
S
S
Department of Surgery, Helsingborg Hospital, Lund University, Sweden.
Qvarfordt
P
P
Plate
G
G
D000818:Animals; D002374:Catalase / Q000494:pharmacology; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D005609:Free Radicals; D006614:Hindlimb / Q000098:blood supply; D008854:Microscopy, Electron; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D009336:Necrosis / Q000473:pathology; D009504:Neutrophils / Q000502:physiology*; D009195:Peroxidase / Q000378:metabolism; D011817:Rabbits; D015427:Reperfusion Injury / Q000209:etiology* / Q000378:metabolism / Q000517:prevention & control; D013482:Superoxide Dismutase / Q000494:pharmacology
D016166:Free Radical Scavengers; D005609:Free Radicals; D002374:Catalase; D009195:Peroxidase; D013482:Superoxide Dismutase