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 in events related to allergic and nonallergic rhinitis. Furthermore, some effects of SP seem to be greater in subjects suffering from allergic rhinitis than in nonallergic subjects. To investigate if these effects may be partly mediated by histamine release (HR) we studied the influence of SP on HR from 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 patients suffering from allergic rhinitis and eighteen non-allergic subjects receiving 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 content 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 controls (spontaneous release). The same effect was seen in the allergic group (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 higher (p=0.031), whereas Ca-ionophore A23187 did not show this effect. Conclusion: These findings suggest a role of SP in inducing release of histamine from human nasal mucosa, thereby influencing physiologic and pathophysiologic nasal conditions, especially in allergic inflammatory processes.