title: Effects of melatonin on the oxidant/antioxidant status and lung histopathology in rabbits exposed to cigarette smoke.
abstract: OBJECTIVE
  To evaluate the effects of cigarette smoking on the histopathology and the oxidant/antioxidant status of the lungs and to test the potential antioxidant benefits of melatonin on these induced changes.
  
  
  METHODS
  Rabbits were exposed to cigarette smoke in a glass chamber for 1 h daily for 1 month with or without intraperitoneal melatonin injection. A melatonin control group was given intraperitoneal melatonin only. A control group was exposed to clean air only. At the end of 1 month, animals were sacrificed and lung tissues were examined histopathologically. Blood levels of protein sulphydryls, carbonyls, prostaglandin F2alpha (PGF2alpha), malondialdehyde (MDA), glutathione peroxidase and superoxide dismutase (SOD) were measured.
  
  
  RESULTS
  Intraparenchymal vascular congestion and thrombosis, intraparenchymal haemorrhage, respiratory epithelial proliferation, number of macrophages in the alveolar and bronchial lumen, alveolar destruction, emphysematous changes and bronchoalveolar haemorrhage scores were significantly increased in rabbits exposed to cigarette smoke compared with the control group. Protein sulphydryls and SOD levels were significantly decreased; carbonyls, PGF2alpha and MDA levels were significantly increased in the smoke exposed rabbits. Administration of melatonin to rabbits exposed to cigarette smoke caused a reduction in the bronchoalveolar haemorrhage score and blood carbonyls levels. Other parameters were unaffected by melatonin.
  
  
  CONCLUSIONS
  Exposure to cigarette smoke causes severe histopathological changes and negatively affects the oxidant/antioxidant status in the lungs of rabbits. A low daily dose of melatonin has some protective effects on histopathological changes and oxidant/antioxidant status of the lungs in smoke exposed rabbits.
authors.affiliation: Afyon Kocatepe University Faculty of Medicine, Department of Pulmonary Medicine, Ayfon, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Unlu
authors.forename: Fatma
authors.initials: F
authors.lastname: Fidan
authors.forename: Murat
authors.initials: M
authors.lastname: Sezer
authors.forename: Levent
authors.initials: L
authors.lastname: Tetik
authors.forename: Onder
authors.initials: O
authors.lastname: Sahin
authors.forename: Hidir
authors.initials: H
authors.lastname: Esme
authors.forename: Tulay
authors.initials: T
authors.lastname: Koken
authors.forename: Mustafa
authors.initials: M
authors.lastname: Serteser
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015237:Dinoprost / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008550:Melatonin / Q000008:administration & dosage / Q000494:pharmacology*; D011817:Rabbits; D012907:Smoking; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D000975:Antioxidants; D008315:Malondialdehyde; D015237:Dinoprost; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D008550:Melatonin