title: The role of leukocytes in the pathophysiology of skeletal muscle ischemic injury.
abstract: Neutrophilic leukocytes have been implicated as important mediators of ischemic myocardial injury. We investigated the role of neutrophils in skeletal muscle ischemia/reperfusion injury by using the rat hindlimb ischemia model. We rendered Wistar rats neutropenic by administering 750 rad of whole-body radiation (mean white blood cell count, 300 +/- 50/mm3; 3 days after radiation). In anesthetized rats (10 neutropenic and 10 control), 3 hours of ischemia were induced in one hindlimb by application of a tourniquet to the proximal thigh; the contralateral limb served as an internal, nonischemic control. After 1 hour of reperfusion the gastrocnemius and soleus muscles were excised bilaterally and evaluated for ischemic injury by means of a quantitative spectrophotometric assay of triphenyltetrazolium chloride (TTC) reduction. In control rats the reduction of TTC by ischemic muscle averaged 27.0% +/- 7.3% of that by nonischemic muscle; whereas in neutropenic rats the value for ischemic muscle was 65.4 +/- 11.6% (p less than 0.05). To determine if the contribution of the neutrophils to ischemic injury is due to oxygen-derived free radical formation, an additional 10 animals were infused with 5000 units of super-oxide dismutase and 10,000 units of catalase at the time reperfusion was restored. After treatment with free radical scavengers, TTC reduction by ischemic limbs was 25.5% +/- 7.0% of that by nonischemic limbs and did not differ from that in control animals (p greater than 0.05). The results show a protective effect of neutropenia and suggest a significant role of the white cell in the pathophysiology of ischemic skeletal muscle injury.
authors: Department of Surgery, Boston University Medical Center, Mass.
authors: M
authors: M
authors: Belkin
authors: W L
authors: WL
authors: LaMorte
authors: J G
authors: JG
authors: Wright
authors: R W
authors: RW
authors: Hobson
mesh_terms: D000818:Animals; D004487:Edema / Q000503:physiopathology; D006614:Hindlimb; D008297:Male; D009132:Muscles / Q000098:blood supply*; D009503:Neutropenia / Q000209:etiology; D009504:Neutrophils / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D015427:Reperfusion Injury / Q000503:physiopathology*; D013053:Spectrophotometry; D013194:Staining and Labeling; D013778:Tetrazolium Salts; D014916:Whole-Body Irradiation
chemical_list: D013778:Tetrazolium Salts; C009591:triphenyltetrazolium