Effect of dexamethasone on expression of sensory neuropeptide substance P in asthmatic mice / 国际儿科学杂志

ABSTRACT

Objective:To explore the effect of dexamethasone on the expression of sensory neuropeptide substance P(SP)in asthmatic mice.Methods:Thirty-two BALB/c mice 6~7 weeks were randomly divided into 4 groups control group, asthmatic group, WIN 62, 577(SP receptor antagonist)intervention group and dexamethasone intervention group.The acute asthma models were established in BALB/c mice by sensitizing and challenging with ovalbumin.The WIN 62, 577 intervention group was given WIN 62, 577 300 μg intraperitoneal injection 1h before each challenge, once a day for 7 consecutive days; the dexamethasone group was given intraperitoneal injection of dexamethasone 2 mg/kg 1h before each challenge, once a day for 7 consecutive days.Results:ELISA results showed that the level of SP[(45.78±9.15)ng/L] in BALF in the asthmatic group was significantly higher than that in the control group[(17.02±2.80)ng/L]( P<0.01); the SP level in BALF in the WIN 62, 577 intervention group [(25.26±3.48)ng/L]was significantly lower than that in the asthmatic group[(45.78±9.15)ng/L]( P<0.01); compared with the asthmatic group[(45.78±9.15)ng/L], the SP level in BALF was significantly reduced after dexamethasone intervention[(34.03±4.38)ng/L]( P=0.002). Compared with the control group[(6883.32±1734.89)ng/L], the level of SP in the serum of mice in the asthmatic group[(1 0247.62±2 667.38)ng/L] was significantly higher( P=0.001); compared with the asthmatic group[(10 247.62±2 667.38)ng/L], the level of SP in the serum of the WIN 62, 577 intervention group[(4 285.99±1 926.36)ng/L] was significantly lower( P<0.01); compared with the asthmatic group[(10 247.62±2 667.38)ng/L], the serum SP level was significantly reduced after dexamethasone intervention [(6 787.22±1 907.45)ng/L]( P=0.001). The results of immunohistochemistry showed that SP and NK-1R expression could be seen in the mouse airway epithelium, perivascular and smooth muscle layer; compared with the control group, SP and NK-1R expression in the airway of asthmatic mice was significantly increased; compared with the asthmatic group, SP and NK-1R expression in the airway of WIN 62, 577 intervention group and dexamethasone intervention group was significantly decreased. Conclusion:Dexamethasone inhibited the expression of SP in the airway of asthmatic mice.