Dose-dependent decrease in anti-oxidant capacity of whole blood after irradiation: A novel potential marker for...

Area of Science:

• Radiation Biology
• Biochemistry
• Toxicology

Background:

• Mitochondrial reactive oxygen species (ROS) production after radiation is well-documented in cell lines.
• Limited data exists on redox homeostasis in irradiated animals and humans.
• Whole-blood antioxidant capacity is an understudied aspect of redox homeostasis, unlike plasma/serum studies.

Purpose of the Study:

• To investigate changes in whole-blood antioxidant capacity following X-ray irradiation in mice.
• To evaluate the potential of blood redox state as a biomarker for radiation exposure.

Main Methods:

• C57BL/6J mice were exposed to X-ray doses ranging from 0.5-3 Gy.
• Whole-blood antioxidant capacity was measured using electron spin resonance (ESR) spin trapping with a novel agent (DPhPMPO).
• Red blood cell (RBC) glutathione and lipid peroxidation levels were assessed.

Main Results:

• Whole-blood antioxidant capacity decreased dose-dependently from 2 to 24 days post-irradiation (r > 0.9, P < 0.05).
• RBC glutathione levels decreased, and lipid peroxidation increased dose-dependently from 2 to 6 days post-irradiation.
• A strong correlation was observed between radiation dose and reduced antioxidant capacity.

Conclusions:

• Whole-blood antioxidant capacity significantly decreases after X-ray irradiation in a dose-dependent manner.
• RBC glutathione reduction and increased lipid peroxidation contribute to the observed changes.
• Blood redox state shows promise as a biomarker for estimating radiation exposure doses in nuclear or radiation accidents.