Related Experiment Video

Updated: Apr 16, 2026

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
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Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Published on: February 16, 2022

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[On the mechanism of radioprotective effect of NO-synthase inhibitors]

M V Filimonova, L I Shevchenko, T P Trofimova

    Radiatsionnaia Biologiia, Radioecologiia
    |March 18, 2015
    PubMed

    Insights

    Selective inhibition of endothelial nitric oxide synthase (NOS) induces hypoxia, conferring radioprotective effects. This suggests potential for developing new radioprotectors targeting endothelial NOS.

    Area of Science:

    • Pharmacology
    • Radioprotection
    • Physiology

    Context:

    • Nitric oxide synthase (NOS) inhibitors are explored for radioprotective potential.
    • Understanding NOS isoform selectivity is crucial for predicting therapeutic effects.
    • Hemodynamic responses to NOS inhibition vary based on isoform selectivity.

    Purpose:

    • To investigate the hemodynamic and radioprotective effects of two isothiourea derivatives with differing NOS isoform selectivity.
    • To determine the role of NOS isoform selectivity in mediating radioprotection.
    • To elucidate the mechanism underlying the radioprotective activity of NOS inhibitors.

    Summary:

    • T1023, an endothelial and inducible NOS inhibitor, induced prolonged hypotension and significant reduction in systemic blood flow, creating hypoxic conditions.
    • NTT2, a neuronal NOS inhibitor, caused vasodilation and maintained systemic blood flow.
    • T1023 demonstrated significant radioprotective effects in mice and bone marrow stem cells, while NTT2 did not.
    • Radioprotection by NOS inhibitors appears to be mediated by hypoxia induction, particularly via endothelial NOS suppression.

    Impact:

    • The findings support hypoxia induction as the primary mechanism for radioprotection by NOS inhibitors.
    • Selective inhibition of endothelial NOS is identified as a key factor for effective radioprotective activity.
    • This research provides a basis for designing novel radioprotectors targeting endothelial NOS for radiation therapy and exposure mitigation.

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