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2. Combination of drugh elevating extracellular adenosine with granulocyte colony-stimulating factor promotes granulopoietic recovery in the murine bone marrow after 5-fluorouracil treatment

Creator:
Michal Hofer, Pospíšil, M., Lenka Weiterová, Vladimír Znojil, Vácha, J., Jiřina Holá, Antonín Vacek, and Iva Pipalová
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, granulocyty, granulocytes, 5-fluorouracil, granulopoiesis, extracellular adenosine, adenosine monophosphate, dipyridamole, granulocyte colony-stimulating factor, 14, and 612
Language:
English
Description:
Combined administration of drugs elevating extracellular adenosine, namely dipyridamole and adenosine monophosphate, together with granulocyte colony-stimulating factor was shown to enhance granulopoietic recovery in the bone marrow of mice treated with 5-fluorouracil. Enhanced regeneration was found both at the level of hematopoietic progenitor cells for granulocytes and macrophages and in the compartment of morphologically recognizable granulocyte precursors. The results might have positive clinical impact. The adjunct use of drugs elevating extracellular adenosine might reduce the cost expenditure of therapy with granulocyte colony-stimulating factor., M. Hofer, M. Pospíšil, L. Weiterová, V. Znojil, J. Vácha, J. Holá, A. Vacek, I. Pipalová., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Enhancement of haemopoietic spleen colony formation by drugs elevating extracellular adenosine: effects of repeated in vivo treatment

Creator:
Hofer, M., Pospíšil, M., Netíková, J., Znojil, V., and Vácha, J.
Type:
article, model:article, and TEXT
Subject:
haemopoietic stem cells, dipyridamole, and adenosine monophosphate
Language:
English
Description:
The potential role of adenosine receptor signalling in the amplification of haemopoietic stem cells in vivo was investigated. Elevation of extracellular adenosine in mice was induced by the joint administration of dipyridamole, a drug inhibiting the cellular uptake of adenosine, and adenosine monophosphate, an adenosine prodrug. The response of haemopoietic stem cells to the drug treatment was measured by endogenous spleen colony-forming assay in sublethally gamma-irradiated animals. The combination of drugs was administered before irradiation either singly or repeatedly at 24 h intervals. The results demonstrated the possibility of enhancing the spleen colony formation by the drug treatment. The highest stimulatory effect on spleen colony counts and on the colony sizes occurred after 3-4 injections of the drugs. Higher spleen colony responses were observed under injection regimens terminated 3 h before irradiation, as compared to those terminated 24 h before the radiation exposure. The results are interpreted as an evidence of the expansion of the stem cell pool. A tolerance to this stimulatory action developed after more than 3 injections of the drugs.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Radioprotective efficacy of dipyridamole and AMP combination in fractionated radiation regimen, and its dependence on the time of administration of the drugs prior to irradiation

Creator:
Hofer, M., Pospíšil, M., Netíková, J., Znojil, V., Vácha, J., and Holá, J.
Type:
article, model:article, and TEXT
Subject:
radioprotection, fractionated irradiation, haemopoiesis, adenosine monophosphate, and dipyridamole
Language:
English
Description:
We have recently demonstrated that the combined administration of dipyridamole and adenosine monophospate to mice induces radioprotective effects in terms of postirradiation haemopoietic recovery in animals irradiated with a single dose. The aim of the present experiments was to investigate the radioprotective ability of the drug combination under conditions of fractionated radiation treatment. It has been shown that administration of drugs either 15 or 60 min before each of the five daily 3-Gy doses of gamma-radiation enhances haemopoietic recovery and survival of mice exposed to an additional "top-up" dose of 3.5 Gy. Furthermore, it has been ascertained that the regimen using administration of the drugs 60 min prior to irradiation is more effective than administration of the drugs 15 min prior to irradiation. Due to the evidence that administration of the drugs 15 min prior to irradiation protects the organism mainly via mechanisms of systemic hypoxia while the pretreatment 60 min before irradiation avoids the role of hypoxia and mainly induces cell proliferation effects, our results suggest a more effective protective role of mechanisms stimulating haemopoiesis under conditions of fractionated radiation. The data may provide a basis for more rational use of radioprotection in fractionated radiation regimens.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public