Substance P induced histamine release from nasal mucosa of subjects with and without allergic rhinitis

Objective and Design. There is evidence that substance P (SP) is involved i n events related to allergic and nonallergic rhinitis. Furthermore, some ef fects of SP seem to be greater in subjects suffering from allergic rhinitis than in nonallergic subjects. To investigate if these effects may be partl y mediated by histamine release (HR) we studied the influence of SP on HR f rom nasal mucosa of subjects with and without allergic rhinitis using an in vitro organ culture system. Subjects: Nasal mucosa of the inferior turbinate was obtained from ten pati ents suffering from allergic rhinitis and eighteen non-allergic subjects re ceiving surgical therapy for nasal obstruction. Methods: Tissue samples of nasal mucosa were stimulated with 10(-5) M SP or with 10(-5) M Ca-ionophore A23187 for 120 minutes, and the histamine conte nt was determined in the culture supernatant. Results: Both SP and Ca-ionophore A23187, caused a significantly higher HR from the samples of the non-allergic group (p<0.01) compared to baseline co ntrols (spontaneous release). The same effect was seen in the allergic grou p (p<0.01 and p=0.036). Comparing the increase in HR from allergic and non- allergic mucosa, in allergies the HR stimulated by SP was significantly hig her (p=0.031), whereas Ca-ionophore A23187 did not show this effect. Conclusion: These findings suggest a role of SP in inducing release of hist amine from human nasal mucosa, thereby influencing physiologic and pathophy siologic nasal conditions, especially in allergic inflammatory processes.