Related Experiment Video
Updated: May 5, 2026

Immunostimulatory Agent Evaluation: Lymphoid Tissue Extraction and Injection Route-Dependent Dendritic Cell Activation
Published on: September 16, 2018
Inducible nitric oxide synthase (iNOS) in sinonasal polyp pathogenesis
N Bayar Muluk1, O K Arikan, P Atasoy
1ENT Department, Kirikkale University, Faculty of Medicine, Kirikkale, Turkey. nurayb@hotmail.com
Inducible nitric oxide synthase (iNOS) is implicated in sinonasal polyp development, particularly in deeper mucosal layers. This suggests iNOS contributes to inflammation and fluid buildup characteristic of nasal polyps.
Area of Science:
- Otorhinolaryngology
- Immunology
- Pathophysiology
Background:
- Sinonasal polyps are inflammatory masses in the upper airway.
- The precise molecular mechanisms driving polyp formation remain incompletely understood.
Purpose of the Study:
- To investigate the role of inducible nitric oxide synthase (iNOS) in the pathogenesis of sinonasal polyps.
Main Methods:
- Adult patients with nasal polyposis and controls underwent functional endoscopic sinus surgery.
- Polyp and control specimens were analyzed for inflammatory cell counts and iNOS expression across eight mucosal layers.
- An iNOS positivity index (PI) was calculated for epithelial, subepithelial, and deep mucosal layers.
Main Results:
- Higher polymorphonuclear cell (PMNC) percentages and ethmoid sinus iNOS PI were observed in the polyp group.
- Factors like polyp duration and patient age influenced iNOS expression patterns in specific sinus regions and mucosal layers.
- iNOS expression in endothelial cells varied between ethmoid/maxillary sinuses and the nasal cavity.
Conclusions:
- iNOS appears to play a significant role in sinonasal polyp pathogenesis, especially within the subepithelial and deep mucosal layers.
- iNOS may contribute to polyp formation through increased vascular permeability, edema, inflammatory cell infiltration, and glandular hypersecretion.
More Related Videos
09:56Intra-tracheal Administration of Haemophilus influenzae in Mouse Models to Study Airway Inflammation
Published on: March 2, 2016
08:32Application of Genetically Encoded Fluorescent Nitric Oxide (NO•) Probes, the geNOps, for Real-time Imaging of NO• Signals in Single Cells
Published on: March 16, 2017
Related Concept Videos
Nitric Oxide Signaling Pathway
Inhibitors of Viral Protein Synthesis
siRNA - Small Interfering RNAs
In the cytoplasm, siRNA is processed from a double-stranded RNA, which comes from either endogenous DNA transcription or exogenous sources like a virus. This double-stranded RNA is then cleaved by the...
Inflammatory Bowel Disease III: Crohn's Disease
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Anatomy of Respiratory System I: Upper Respiratory Tract
Nose and nasal cavity
The nose and nasal cavity represent the main external openings of the respiratory tract....