title: Melatonin protects kidney against apoptosis induced by acute unilateral ureteral obstruction in rats.
abstract: BACKGROUND
  To investigate whether there was a protective effect of melatonin on apoptotic mechanisms after an acute unilateral obstruction of the kidney.
  
  
  METHODS
  A total of 25 rats consisting of five groups were used in the study, designated as follows: Group 1: control, Group 2: sham, Group 3: unilateral ureteral obstruction treated with only saline, Group 4: unilateral ureteral obstruction treated with melatonin immediately, and Group 5: unilateral obstruction treated with melatonin one day after obstruction. Melatonin was administered as a 10 mg/kg dose intraperitoneally. The kidneys were evaluated according to the apoptotic index and Ki-67 scores.
  
  
  RESULTS
  Comparison of all obstruction groups (Group 3, 4, and 5), revealed that the apoptotic index was significantly higher in Groups 1 and 2. Despite melatonin reduced apoptotic mechanisms in Groups 4 and 5, there was no significant difference between Groups 4 and 5 in terms of the reduction of apoptosis. However, the reduction of apoptosis in the melatonin treated group did not decrease to the level of Groups 1 and 2.
  
  
  CONCLUSIONS
  Despite melatonin administration, which significantly reduces the apoptotic index occurring after acute unilateral ureteral obstruction, the present study did not observe a return to normal renal histology in the obstruction groups.
authors.affiliation: Turgut Özal University School of Medicine, Department of Urology, Ankara, Turkey.
authors.forename: Mehmet Erol
authors.initials: ME
authors.lastname: Yildirim
authors.affiliation: Behçet Uz Research and Training Hospital, Department of Urology, Izmir, Turkey.
authors.forename: Hüseyin
authors.initials: H
authors.lastname: Badem
authors.affiliation: Turgut Özal University School of Medicine Department of Internal Medicine, Ankara, Turkey.
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Cakmak
authors.affiliation: Ankara Oncology Research and Training Hospital, Department of Urology, Ankara, Turkey.
authors.forename: Hakki
authors.initials: H
authors.lastname: Yilmaz
authors.affiliation: Turgut Özal University School of Medicine Department of Anesthesiology, Ankara, Turkey.
authors.forename: Bahadir
authors.initials: B
authors.lastname: Kosem
authors.affiliation: Ankara Atatürk Research and Training Hospital, Department of Urology, Ankara, Turkey.
authors.forename: Omer Faruk
authors.initials: OF
authors.lastname: Karatas
authors.affiliation: Turgut Özal University School of Medicine Department of Pathology, Ankara, Turkey.
authors.forename: Reyhan
authors.initials: R
authors.lastname: Bayrak
authors.affiliation: Turgut Özal University School of Medicine, Department of Urology, Ankara, Turkey.
authors.forename: Ersin
authors.initials: E
authors.lastname: Cimentepe
keywords: antioxidant; apoptosis; hypoxia; kidney; melatonin; obstruction