[The experimental study on the biological rhythm expression of substance P in allergic airway inflammation mice]

OBJECTIVE: To establish the murine models of allergic airway inflammation, and to investigate the biological rhythm expression of substance P in it. METHOD: Eighty-four BALB/c mice were divided into 14 groups, which were airway inflammation groups(0: 00 group, 04: 00 group, 08: 00 group, 12: 00 group, 16: 00 group, 20: 00 group, 24: 00 group) and normal control groups(0: 00 group, 04: 00 group, 08: 00 group, 12: 00 group, 16: 00 group, 20: 00 group, 24: 00 group). The allergic airway inflammation models of mice were established by intraperitoneal injection of ovalbumin(OVA), nasal challenge and aerosol inhalation with OVA. The plasma substance P levels were measured by ELISA. The expression of substance P in nasal mucosa, left lung tissue and left bronchial tissue during different time periods was obversed with RT-PCR and immunohistochemical technique. RESULT: In allergic airway inflammation groups, the plasma substance P levels were higher than in normal control groups(P < 0.05), and 0: 00 group(321.99±28.93) pg/mL, 04: 00 group(310.76±25.31) pg/mL and 24: 00 group(335.62±28.29) pg/mL were higher than other experimental groups(P < 0.05). The expression of substance P mRNA in nasal mucosa, left lung tissue and left bronchial tissue was higher than control groups(P < 0.01). By observing immunohistochemical sections, the expression of substance P in allergic airway inflammation groups was higer than control groups. CONCLUSION: The expression of substance P is high in allergic airway inflammation mice and the peaks are during 04: 00-08: 00 in the early morning, which may provide new basis for treating allergic airway inflammation.