Radioprotection of mice by the bacterial extract Broncho-Vaxom: haemopoietic stem cells and survival enhancement.
Pretreatment of mice with 50-1000 micrograms of the bacterial extract Broncho-Vaxom (BV, free of endotoxin) before sublethal irradiation induced an increase in the number of endogenous haemopoietic stem cells (E-CFU). The degree of radioprotection was dependent on both the time of administration and the dose of BV. An optimal E-CFU survival was observed when 500 micrograms of BV was administered i.p. 24 h before irradiation. BV did not affect the day 9 CFU-S survival in the bone marrow directly after irradiation. However, 5, 9 and 12 days after irradiation, the number of day 9 CFU-S was almost 2-fold higher in the bone marrow of BV injected mice. Pretreatment with BV protected C57B1/6 mice in a dose-dependent manner from the lethal effect of ionizing radiation. A single dose (50, 100, 250, or 500 micrograms) of bacterial lysate injected i.p. 24 h before 9.5 Gy gamma-rays (LD100/21) protected 16%, 25%, 80%, and 94% of C57B1/6 mice, respectively. The dose reduction factor in the case when the BV (500 micrograms per mouse) was administered at that time was 1.18 (95% CL 1.12, 1.25).
Department of Cellular and Molecular Biology, Faculty of Sciences, P. J. Safárik University, Kosice, Czech and Slovak Federative Republic.
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Fedorocko
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Brezáni
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Macková
D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000818:Animals; D001419:Bacteria; D002457:Cell Extracts; D002470:Cell Survival / Q000528:radiation effects; D005260:Female; D006412:Hematopoietic Stem Cells / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D011833:Radiation Injuries, Experimental / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000627:therapeutic use*; D000095983:Bacterial Lysates
D000276:Adjuvants, Immunologic; D002457:Cell Extracts; D011837:Radiation-Protective Agents; C030259:Broncho-Vaxom; D000095983:Bacterial Lysates