Effect of tramadol on lung injury induced by skeletal muscle ischemia-reperfusion: an experimental study.
OBJECTIVE
To determine whether tramadol has a protective effect against lung injury induced by skeletal muscle ischemia-reperfusion.


METHODS
Twenty Wistar male rats were allocated to one of two groups: ischemia-reperfusion (IR) and ischemia-reperfusion + tramadol (IR+T). The animals were anesthetized with intramuscular injections of ketamine and xylazine (50 mg/kg and 10 mg/kg, respectively). All of the animals underwent 2-h ischemia by occlusion of the femoral artery and 24-h reperfusion. Prior to the occlusion of the femoral artery, 250 IU heparin were administered via the jugular vein in order to prevent clotting. The rats in the IR+T group were treated with tramadol (20 mg/kg i.v.) immediately before reperfusion. After the reperfusion period, the animals were euthanized with pentobarbital (300 mg/kg i.p.), the lungs were carefully removed, and specimens were properly prepared for histopathological and biochemical studies.


RESULTS
Myeloperoxidase activity and nitric oxide levels were significantly higher in the IR group than in the IR+T group (p = 0.001 for both). Histological abnormalities, such as intra-alveolar edema, intra-alveolar hemorrhage, and neutrophil infiltration, were significantly more common in the IR group than in the IR+T group.


CONCLUSIONS
On the basis of our histological and biochemical findings, we conclude that tramadol prevents lung tissue injury after skeletal muscle ischemia-reperfusion.
Islamic Azad University, Faculty of Specialized Veterinary Science, Department of Veterinary Surgery, Tehran, Iran.
Mohammad Ashrafzadeh
MA
Takhtfooladi
Amirali
A
Jahanshahi
Amir
A
Sotoudeh
Gholamreza
G
Jahanshahi
Hamed Ashrafzadeh
HA
Takhtfooladi
Kimia
K
Aslani
D000818:Animals; D004195:Disease Models, Animal; D005263:Femoral Artery; D008168:Lung / Q000473:pathology*; D055370:Lung Injury / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply*; D009569:Nitric Oxide / Q000032:analysis; D009195:Peroxidase / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000150:complications / Q000473:pathology / Q000517:prevention & control*; D014147:Tramadol / Q000627:therapeutic use*
D009569:Nitric Oxide; D014147:Tramadol; D009195:Peroxidase