title: Melatonin attenuates lung injury in a hind limb ischemia-reperfusion rat model.
abstract: OBJECTIVE
  This study evaluated the protective antioxidant effect of melatonin on lung injury as a remote organ after skeletal muscle ischemia-reperfusion in rats.
  
  
  METHODS
  Thirty male Wistar rats were allocated randomly into three experimental groups: operated with no ischemia (Sham) group, ischemia-reperfusion group and ischemia-reperfusion+melatonin group. Hind limb ischemia was induced by clamping the femoral artery. After 2h ischemia, the clamp was removed and the animal underwent 24h reperfusion. Rats in the ischemia-reperfusion + melatonin group received melatonin (10 mg/kg i.v.), immediately before the clamp was removed. At the end of the trial, animals were euthanized and the lungs were removed for water content determination, histopathological and biochemical studies.
  
  
  RESULTS
  In the ischemia-reperfusion + melatonin group, tissues showed less intense histological abnormalities such as neutrophilic infiltration, intra-alveolar hemorrhage and edema compared with the ischemia-reperfusion group. Histopathologically, there was a significant difference (P < 0.05) between the two groups. The lung water content in the ischemia-reperfusion + melatonin group was significantly lower than the ischemia-reperfusion group (P < 0.05). Lung tissue myeloperoxidase (MPO) activity and nitric oxide (NO) level were significantly (P < 0.05) increased by ischemia-reperfusion. The increase in these parameters was reduced by melatonin. Comparing the ischemia-reperfusion+melatonin group with the sham group, no significant increase in all analyzed aspects of the research was observed.
  
  
  CONCLUSIONS
  These findings suggest that melatonin has preventive effects in lung tissue injury after transient femoral artery occlusion.
authors: Faculty of Veterinary Science, Karaj Branch, Islamic Azad University, Karaj, Iran.
authors: Hamed
authors: H
authors: Takhtfooladi
authors: Department of Surgery, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran. Electronic address: dr_ashrafzadeh@yahoo.com.
authors: Mohammad
authors: M
authors: Takhtfooladi
authors: Department of Pathobiology, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran.
authors: Fariborz
authors: F
authors: Moayer
authors: Faculty of Medical Sciences, Shahid Sadughi University, Yazd, Iran.
authors: Sayed
authors: S
authors: Mobarakeh
mesh_terms: D055371:Acute Lung Injury / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use*; D004195:Disease Models, Animal; D035002:Lower Extremity; D008297:Male; D008550:Melatonin / Q000627:therapeutic use*; D018482:Muscle, Skeletal / Q000098:blood supply; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000150:complications
chemical_list: D000975:Antioxidants; D008550:Melatonin
keywords: Histopathology; Ischemia–reperfusion; Lung remote injury; Melatonin; Myeloperoxidase; Nitric oxide