[P-selectin and tachykinins in bronchial hyperresponsiveness of asthma].

OBJECTIVE: The characteristic feature of asthma is bronchial hyperresponsiveness (BHR). It is due predominately to inflammation of airways. Pathologically, there are inflammatory infiltration, epithelial sloughing and mucosal edema in the bronchi. The objective of this study is to investigate the relationship between BHR and airway inflammation. METHODS: 57 cases of asthma and 22 normal subjects were tested with bronchial reactivity examination and P-selectin, substance P (SP) and vasoactive intestinal peptide (VIP) in plasma. RESULTS: It was found that the bronchial reactivity to inhaled methacholine was positive in 53 of the 57 asthmatic patients (92.98%), while the remaining four were negative (7.02%). Twenty-two normal subjects were all negative with the test of bronchial reactivity. The levels of P-selectin and SP in asthmatics with corticosteroids treatment (n = 27) were higher than those in the control group (P < 0.05), but lower than those in asthmatics treated with aminophylline and salbutamol sulfate (n = 30), (P < 0.01). The concentration of VIP in asthmatics with corticosteroids treatment was significantly higher than that of asthmatics with out corticosteroids treatment (P < 0.01) but lower than that in the control group (P < 0.01). There was positive relationship between bronchial reactivity and P-selectin (r = 0.328, P < 0.05), as well as SP (r = 0.529, P < 0.01) in asthmatics, but negative relationship between bronchial reactivity and VIP (r = -0.419, P < 0.05). CONCLUSION: The increase of P-selectin and SP and decrease of VIP can induce BHR, corticosteroids can reduce levels of P-selectin, SP and enhance the level of VIP, therefore it can improve the reactivity of airway and relieve symptoms.