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Updated: Jul 11, 2026
08:23
Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
Published on: February 16, 2022
Localization and thiol dependancy of endogenous nitro compounds-mediating urethral photo-relaxation
D Triguero1, M González-Herreros, G Costa
1Department of Physiology, Veterinary School, Complutense University, 28040 Madrid, Spain. dtriguer@vet.ucm.es
Pflugers Archiv : European Journal of Physiology
|September 18, 2007
Summary
Electrical field stimulation and light stimulation both release nitric oxide (NO) in the urethra. Light-induced NO release, unlike EFS-induced release, depends on glutathione, suggesting photolytic breakdown of S-nitroso-glutathione.
Area of Science:
- Urology
- Neuroscience
- Biochemistry
Background:
- Nitric oxide (NO) plays a crucial role in regulating urethral function.
- Understanding the mechanisms of NO generation and its regulation is essential for treating lower urinary tract disorders.
Purpose of the Study:
- To investigate the cellular sources and mechanisms of NO generation in the urethra induced by electrical field stimulation (EFS) and light stimulation (LS).
- To examine the role of glutathione (GSH) in modulating NO release and urethral relaxation under EFS and LS conditions.
Main Methods:
- Utilized a NO-specific fluorescent probe to detect NO generation in sheep and rat urethral tissues.
- Applied EFS and LS to induce NO release and measured urethral relaxation.
- Investigated the effects of nNOS inhibitors and GSH modifiers (e.g., ethacrynic acid) on NO release and relaxation.
Main Results:
- Both EFS and LS induced NO release from nNOS-immunoreactive nerves.
- EFS-induced responses were blocked by nNOS inhibitors but not significantly affected by GSH depletion.
- LS-induced responses were dependent on GSH, with mitochondrial GSH depletion reducing and eventually abolishing photo-relaxation.
- Photolytic breakdown of an endogenous nitro-compound, likely S-nitroso-glutathione, was identified as the primary mechanism for LS-induced photo-relaxation.
Conclusions:
- NO release in the urethra is mediated by nNOS activation during EFS.
- Light-induced urethral relaxation is primarily mediated by the photolytic breakdown of S-nitroso-glutathione in nitrergic nerves and vascular endothelium.
- This photolytic mechanism may play a role in NO inactivation and protection of NO-generating structures.
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