Influence of exogenous melatonin on doxorubicin-evoked effects in myocardium and in transplantable Morris hepatoma in rats.
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.
Dziegiel
Piotr
P
Department of Histology and Embryology, University School of Medicine, Chalubinskiego 6a, 50-367 Wroclaw, Poland. piotr@hist.am.wroc.pl
Podhorska-Okolow
Marzena
M
Surowiak
Pawel
P
Ciesielska
Urszula
U
Rabczynski
Jerzy
J
Zabel
Maciej
M
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
D000903:Antibiotics, Antineoplastic; D016166:Free Radical Scavengers; D004317:Doxorubicin; D008550:Melatonin