title: Influence of exogenous melatonin on doxorubicin-evoked effects in myocardium and in transplantable Morris hepatoma in rats.
abstract: BACKGROUND
  Melatonin is one of the most effective oxygen free radical scavengers. Its cardio- and nephro-protective effects were demonstrated in the course of anthracycline administration. The present study aimed at examining the cytostatic efficiency of doxorubicin (DOX) applied together with melatonin to rats with transplantable Morris hepatoma.
  
  
  METHODS
  Animals were divided into four groups receiving 0.9% NaCl, melatonin, DOX and melatonin together with DOX, respectively. Three weeks after transplantation of the tumour cells, the heart and tumour were isolated. The extent of tumour necrosis and the number of apoptotic cells were evaluated in paraffin-embedded sections.
  
  
  RESULTS
  Administration of melatonin together with DOX decreased the extent of tumour necrosis and the apoptotic tumour cells but, on the other hand, decreased the number of apoptotic cardiomyocytes.
  
  
  CONCLUSIONS
  Melatonin weakens the cytotoxic activity of DOX by the decreased proportions of necrotic and apoptotic cells of transplantable Morris hepatoma. Melatonin protects also cardiomyocytes by decreasing DOX-induced apoptosis in the cells.
authors.affiliation: Department of Histology and Embryology, University School of Medicine, Chalubinskiego 6a, 50-367 Wroclaw, Poland. piotr@hist.am.wroc.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Dziegiel
authors.forename: Marzena
authors.initials: M
authors.lastname: Podhorska-Okolow
authors.forename: Pawel
authors.initials: P
authors.lastname: Surowiak
authors.forename: Urszula
authors.initials: U
authors.lastname: Ciesielska
authors.forename: Jerzy
authors.initials: J
authors.lastname: Rabczynski
authors.forename: Maciej
authors.initials: M
authors.lastname: Zabel
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D002452:Cell Count; D004317:Doxorubicin / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D016166:Free Radical Scavengers / Q000627:therapeutic use*; D020287:In Situ Nick-End Labeling; D008114:Liver Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology; D008550:Melatonin / Q000627:therapeutic use*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000473:pathology; D009336:Necrosis; D009368:Neoplasm Transplantation; D051381:Rats
chemical_list: D000903:Antibiotics, Antineoplastic; D016166:Free Radical Scavengers; D004317:Doxorubicin; D008550:Melatonin