[The effect of 5-fluorouracil on the radiosensitivity of granulocytopoietic stem cells in the bone marrow and the blood].
The radiation tolerance of haematopoietic stem-cells, originating from blood and bone marrow, after exposure to 5-Fluorouracil (5-FU) was investigated. The CFU-C Colony Formation Test was used to determine the surviving fraction of cryopreserved mononuclear bone marrow and blood cells, after incubation in culture medium containing 1 ng/ml 5-FU for 24 hours. With the same assay system we determined the radiation tolerance of peripheral CFU-C from three patients before and after 5-FU radio-chemotherapy (1000 mg/m2/24 h per day for four days), while the influence of the small radiotherapeutic treatment volume was neglected. Neither in the in vitro experiments nor in the patients we found a significant variation of the dose-survival curves with or without 5-FU. So it is concluded, that the enhanced myelodepression of 5-FU combined with radiation may be due to an additive effect or by effects on the microenvironment or on the pluripotent stem cell system.
Kodym
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Universitätsklinik für Strahlentherapie und Strahlenbiologie, Wien, Osterreich.
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D003131:Combined Modality Therapy; D005472:Fluorouracil / Q000494:pharmacology* / Q000627:therapeutic use; D006098:Granulocytes / Q000166:cytology* / Q000187:drug effects; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D006412:Hematopoietic Stem Cells / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D011836:Radiation Tolerance / Q000187:drug effects*
D005472:Fluorouracil
Wirkung von 5-Fluorouracil auf die Strahlensensibilität von granulozytopoetischen Stammzellen des Knochenmarks und des Blutes.