Effect of neurokinin 1 receptor antagonist on airway inflammation and hyperresponsiveness in asthmatic mice

Objective To investigate the effects of neurokinin-1 receptor antagonist WIN 62, 577 on airway inflammation and airway hyperresponsiveness in asthmatic mice. Methods Thirty-two BALB/c mice(Specific-pathogen-free grade) were randomly divided into 4 groups: control group, asthmatic group, WIN 62, 577 intervention group and dexamethasone group.The asthmatic group, the WIN 62, 577 intervention group, and the dexamethasone group were given intraperitoneal injection of 0.2 ml of OVA sensitization solution at 0 d, 7 d, and 14 d, respectively.Then the asthmatic group, WIN 62, 577 group and dexamethasone group were given OVA challenge solution(4% OVA solution) by inhalation once a day for 30 min from 21 d to 28 d for 7 consecutive days.The WIN 62, 577 intervention group was given WIN 62, 577 300 μg intraperitoneal injection 1 h before each challenge; the dexamethasone group was given intraperitoneal injection of dexamethasone 2 mg/kg 1 h before each challenge.The airway responsiveness of each group of mice was detected by non-invasive pulmonary function test.The bronchoalveolar lavage fluid(BALF) was obtained for inflammatory count.The HE staining of lung tissue was used to observe airway inflammation in mice. Results Compared with the asthmatic group, the mice in the WIN 62, 577 intervention group showed less restlessness, standing upright, crouching back, scratching the ears and scratching the cheeks, shortness of breath and cyanosis of the lips.After inhaling different concentrations of acetylcholine, the Penh value of mice in the WIN 62, 577 intervention group and the dexamethasone group was significantly lower than that in the asthmatic group(P<0.05). Compared with the asthmatic group, the number of WBC and EOS in BALF decreased significantly in the WIN 62, 577 intervention group and the dexamethasone group(P<0.01). HE staining showed that the inflammatory changes in the lung tissue of mice in the WIN 62, 577 intervention group were significantly reduced, the bronchial epithelium did not fall off significantly, the mucosal edema was not obvious, the smooth muscle proliferation was reduced, and the inflammatory cell infiltration was reduced, similar to the airway changes in the dexamethasone group. Conclusion Neurokinin-1 receptor antagonist WIN 62, 577 can reduce airway inflammation and airway hyperresponsiveness in asthmatic mice. Key words: Asthma; Inflammation; Hyperresponsiveness; Substance P; Neurokinin-1 receptor