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Updated: Jan 2, 2026

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
Published on: February 16, 2022
Nitric oxide radicals choreograph a radioadaptive response
Hideki Matsumoto1, Akihisa Takahashi, Takeo Ohnishi
1Division of Oncology, Biomedical Imaging Research Center, University of Fukui, Fukui, Japan. hidekim@u-fukui.ac.jp
Low-dose radiation exposure induces cellular resistance to high-dose radiation, known as the radioadaptive response. This study reveals that nitric oxide (NO) radicals are key initiators of this radiation resistance phenomenon.
Area of Science:
- Cellular biology
- Radiation biology
- Biochemistry
Background:
- The radioadaptive response describes reduced biological effects from radiation after low-dose conditioning exposures.
- Observed endpoints include chromosomal aberrations, mutations, and survival, but mechanisms remain unclear.
Purpose of the Study:
- To investigate the role of radiation-induced nitric oxide (NO) radicals in the radioadaptive response.
Main Methods:
- Exposing cells to low-dose gamma or X-rays followed by high-dose X-irradiation.
- Measuring inducible NO synthase accumulation and nitrite concentration.
- Utilizing NO synthase inhibitors, NO radical scavengers, and NO radical-generating agents.
Main Results:
- Low-dose radiation exposure increased inducible NO synthase and nitrite levels.
- Inhibition of NO synthase or scavenging of NO radicals abolished radioresistance.
- NO radical-generating agents induced radioresistance.
Conclusions:
- Radiation-induced nitric oxide (NO) radicals play a critical role in initiating the radioadaptive response.
- NO radicals contribute to cellular radioresistance after low-dose conditioning exposures.
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