Histological and histochemical examinations of myocardium of rats kept on low-magnesium diet and receiving methotrexate.
Methotrexate administration in 1 mg/kg doses intraperitoneally twice weekly for six weeks caused in rat myocardium the following focal, not very intense, histological and histochemical changes from the third week of the experiment on: focal increasing eosinophilia and fuchsinophilia of myocyte cytoplasm, undulating shape of myocardial fibres, contraction nodes, in the sixth week small necrotic foci with associated infiltrations composed of mononuclear cells, presence of p.a.S. positive substance resistant to diastase digestion in foci of damaged cardiomyocytes, focal rise of acid phosphatase, local loss of calcium and magnesium dependent ATPases in the sixth week, and unchanged succinic dehydrogenase activity. Simultaneous administration of low-magnesium diet and methotrexate caused more frequent (from the second week on) the appearance of more intense degenerative changes, and from the third week on the appearance of necrotic changes of cardiomyocytes, local increase of acid phosphatase activity from the second week on, falling activity of calcium and magnesium dependent ATPases from the fifth week on, and losses of succinic dehydrogenase activity in the sixth week of the experiment.
Wutzen
J
J
Department of Cell Pathophysiology, Medical Centre of Postgraduate Education, Warszawa, Poland.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000284:Administration, Oral; D000818:Animals; D006321:Heart / Q000187:drug effects; D008274:Magnesium / Q000008:administration & dosage; D008275:Magnesium Deficiency / Q000378:metabolism*; D008297:Male; D008727:Methotrexate / Q000633:toxicity*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains
D000251:Adenosine Triphosphatases; D008274:Magnesium; D008727:Methotrexate