Reduced bone marrow pO2 following treatment with radioprotective drugs.

Abstract

The sensitizer adduct technique [( 3H]misonidazole binding) was used to assess the extent of murine bone marrow hypoxia following treatment with a variety of radioprotectors. The binding rates previously determined in vivo were compared to those obtained by incubating marrow cells in atmospheres of varying oxygen content. Parallel experiments demonstrated that the oxygen dependence of [3H]misonidazole binding (Km approximately 0.15% oxygen) was similar to the oxygen dependence of marrow radiosensitivity (Km approximately 0.2% oxygen). Maximally radioprotective doses of several drugs have been shown to increase the binding of [3H]misonidazole significantly in vivo. A comparison to the in vitro binding rates suggests that the average oxygen concentration in the marrow at times associated with radioprotection was on the order of 0.5 to 0.8% oxygen. The relative importance of marrow hypoxia to the overall radioprotective effects of different drugs may vary considerably. However, these results have demonstrated that certain radioprotective drugs can induce marrow hypoxia and this reduced pO2 may contribute to the efficacy of these agents.

• Authors: M J Allalunis-Turner
• Journal: Radiation research (Radiat Res) Vol. 122 Issue 3 Pg. 262-7 (Jun 1990) ISSN: 0033-7587 [Print] United States
• PMID: 2356279 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Radiation-Protective Agents
• Tritium
• Misonidazole

Topics

• Animals
• Bone Marrow (drug effects, metabolism, radiation effects)
• Depression, Chemical
• Female
• In Vitro Techniques
• Mice
• Mice, Inbred C57BL
• Misonidazole
• Oxygen Consumption (drug effects, radiation effects)
• Partial Pressure
• Radiation-Protective Agents (pharmacology)
• Tritium