Increasing alkaline DNase activity with substrate specificity for denaturated DNA after high dose methotrexate therapy.
After high dose methotrexate (CAS 59-05-2) therapy of children with non-metastatic osteosarcoma the activity of an alkaline DNase with substrate specificity for denaturated DNA increases in lymphocytes and PHA-stimulated lymphocytes. The DNase activity is probably involved in the process of DNA repair. The enzyme has an isoelectric point of pI 5.9, the pH optimum is 8.5, and Mg++ is necessary for activation. Two weeks after the end of the therapy the DNase activity is comparable to the activity of controls. The determination of the alkaline DNase activity can represent a parameter to control side effects of a cytostatic therapy. It is an indirect way to demonstrate therapy induced DNA damage.
Department of Physiological Chemistry, University of Mainz, Fed. Rep. of Germany.
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Reitz
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Gutjahr
D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002648:Child; D004247:DNA / Q000378:metabolism*; D004249:DNA Damage; D003851:Deoxyribonucleases / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D066298:In Vitro Techniques; D007525:Isoelectric Focusing; D008214:Lymphocytes / Q000187:drug effects; D008274:Magnesium / Q000494:pharmacology; D008727:Methotrexate / Q000627:therapeutic use*; D009693:Nucleic Acid Hybridization; D012516:Osteosarcoma / Q000378:metabolism; D010835:Phytohemagglutinins; D013379:Substrate Specificity; D013936:Thymidine / Q000378:metabolism
D010835:Phytohemagglutinins; D004247:DNA; D003851:Deoxyribonucleases; D008274:Magnesium; D013936:Thymidine; D008727:Methotrexate