The Role of Substance P Receptor Antagonists in Allergic Rhinitis: Ovalbumin‐Induced Rat Model

Objective Substance P is a peptide from the tachykinin family, which is found in peripheral and central nervous systems, causing vasodilation and increased secretion in the nasal mucosa. In this study, we aimed to investigate whether the experimental model of allergic rhinitis will cause allergic changes in the larynx and to compare the effects of aprepitant, a substance P antagonist, on nasal symptoms in allergic rhinitis, and histopathological changes in the nasal and laryngeal mucosa with antihistamine and leukotriene receptor antagonists (LTRA). Study Design An experimental animal study. Method The study was carried out on 34 healthy 8–12 weeks old female Sprague Dawley rats in 5 groups. The rats in which an experimental allergic rhinitis model was created with ovalbumin were scored by observing their nasal symptoms, and nasal and laryngeal mucous membranes included in the study were evaluated histopathologically after medications. Results As a result of the analysis of the data obtained from the study, antihistamine and LTRA significantly reduced the symptoms of nose scratching and sneezing, while aprepitant did not affect nasal symptoms. In the histopathological examination of the larynx, effects that would make a significant difference were found in the allergy group when compared to the control group. On the larynx, aprepitant reduced pseudostratification significantly compared to the allergy group. Conclusion Aprepitant provides histopathological changes in the treatment of allergic rhinitis, but does not have sufficient effect on nasal symptoms. The effect of aprepitant on the larynx has not been clearly demonstrated. Level of Evidence NA Laryngoscope , 133:2891–2897, 2023