Background/aims: The present study investigated the mechanism by which peroxynitrite impairs vascular function through the nitric oxide (NO)/soluble guanylate cyclase (sGC)/cGMP pathway.
Methods: Mechanical responses of rat external iliac arteries without endothelium were studied under exposure to peroxynitrite. cGMP concentrations were determined by enzyme immunoassay.
Results: Relaxation induced by BAY 41-2272 (sGC stimulator) was impaired under exposure to peroxynitrite, whereas that by BAY 60-2770 (sGC activator) was enhanced. These responses were correlated with tissue levels of cGMP. Effects of peroxynitrite on the relaxant responses to BAY compounds were also observed in the presence of superoxide dismutase (SOD) or tempol, both of which scavenge a certain kind of reactive molecules other than peroxynitrite. As is the case with the relaxant response to BAY 41-2272, acidified NaNO2- and nitroglycerin-induced relaxations were markedly attenuated by exposing the arteries to peroxynitrite, which was not abolished by preincubation with SOD or tempol. On the other hand, peroxynitrite exposure had no effect on the 8-Br-cGMP-induced vasorelxation.
Conclusion: These findings suggest that peroxynitrite interferes with the NO/sGC/cGMP pathway by altering the redox state of sGC. It is likely that peroxynitrite can shift the sGC redox equilibrium to the NO-insensitive state in the vasculature.
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http://dx.doi.org/10.1159/000371491 | DOI Listing |
Children (Basel)
December 2024
Division of Neonatology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
L-citrulline (L-CIT), a precursor to L-arginine (L-ARG), is a key contributor to the nitric oxide (NO) signaling pathway. Endothelial dysfunction, characterized by deficient nitric oxide synthesis, is implicated in the pathogenesis of various neonatal conditions such as necrotizing enterocolitis (NEC) and bronchopulmonary dysplasia (BPD) associated pulmonary hypertension (PH). This review summarizes the current evidence around the possible role of L-CIT supplementation in the treatment of these conditions.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Biochemistry, Jawaharlal Nehru Medical College, Faculty of Medicine, Aligarh Muslim University, Aligarh, Uttar Pradesh, India. Electronic address:
Persistence of long-term hyperglycemia results in the glyco-oxidation of plasma proteins, which is considered to be a significant factor in metabolic dysfunction, linking hyperglycemia to the emergence of vascular complications. Methylglyoxal (MGO), a dicarbonyl species formed excessively under diabetes, elevates the oxidative stress, enhancing the generation of superoxide anion, which ultimately reacts with nitric oxide (NO•) to form peroxynitrite (PON). PON, being a powerful nitro-oxidizing agent distorts protein structure, hampering its function.
View Article and Find Full Text PDFACS Sens
January 2025
State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials Oriented Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Sulfur dioxide (SO), being a novel gaseous signaling molecule, exhibits significant potential for application in the field of cardiovascular diseases. SO donors serve as crucial tools for the transportation and regulation of SO in vivo, facilitating the investigation of physiological roles associated with this molecule. However, the current therapeutic SO donors lack the capability to monitor the real-time release of SO, thereby hindering accurate assessment of their therapeutic efficacy and target localization.
View Article and Find Full Text PDFFront Neurol
January 2025
Independent Laboratory of Experimental Dentistry, Medical University of Białystok, Białystok, Poland.
Introduction: Temporomandibular disorders have a multifactorial etiology including biological, biomechanical, neuromuscular, and biopsychosocial factors. Current research on temporomandibular disorders focuses on identifying clinically relevant biomarkers thus creating a new way of thinking about this dysfunction. The aim of the study was to determine the relationship between salivary/blood concentrations of oxidative/nitrosative stress biomarkers and biopsychosocial findings in patients with temporomandibular disorder-myofascial pain with referral.
View Article and Find Full Text PDFRedox Biol
January 2025
Hubei Key Laboratory of Cognitive and Affective Disorders, Institute of Biomedical Sciences, School of Medicine, Jianghan University, Wuhan, 430056, China; College of Chemistry and Chemical Engineering, Yangtze Normal University, Chongqing, China. Electronic address:
Accurate and selective techniques for visualizing endogenous peroxynitrite (ONOO) in cerebral ischemia-reperfusion injury (CIRI) models are essential for understanding its complex pathological processes. Here, we introduced a longwave fluorescent probe TJO for detecting ONOO rapidly and sensitively, with a low detection limit of 91 nM. Furthermore, TJO exhibits excellent fluorescence imaging capabilities, enabling detailed visualization of ONOO⁻ in CIRI mice model.
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