[Substance P in plasma of patients with allergic rhinitis and its clinical significance].

By using the supersensitive and highly specific SP-radioimmunoassays to measure the concentration of substance P (SP) in the plasma of patients with allergic rhinitis, the authors found that the levels of SP in the plasma had significantly increased as compared with normal controls (P < 0.001). Using the laser-Doppler flowmeter to measure the blood flow in the nasal mucosa, it was also found that the increase in blood flow in the nasal mucosa had a close correlation with the content of SP. The results show that SP could induce vasodilation in nasal mucosa, lead to a significant increase in nasal blood flow. The pathogenetic importance of the neuropeptide SP in allergic rhinitis and the clinical significance of changes in SP in the plasma of subjects with allergic rhinitis has been discussed.