Changes of airway sensory nerves of normal rats after exposed to sulfur dioª²xide of low concentration

    LIN Hanª²Jun£¬QI Haoª²Wen£¬FANG Liª²Ping

    Department of Respiratory Diseases£¬ Xijing Hospital£¬ Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To study the pathological changes of airway injury and the effect on the axon reflex of sensory nerve by the sulfur dioxide (SO2) of low concentration. METHODS£º Sixteen SD male rats were divided randomly into 2 groups: control group and SO2 group. The control group was exposed to pure air. SO2 group was exposed to SO2 at the concentration of 1.0 mg/(m3¡¤h), 6 h daily for consecutive 3 d. At 4th day, we collected the bronchoalveolar lavage fluid (BALF), plasma and lung tissue. Then we counted the total cell number in BALF, measured the plasma SP content and performed the immunohistochemical staining (HE and SP methods) on the lung tissue. RESULTS: Compared with the control group, the total cell number in BALF and plasma SP content in SO2 group increased significantly (P<0.01). HE staining showed there were a great deal of inflammatory cell infiltration under the tunica mucosa bronchiorum; and SP immunohistochemical staining indicated there was a significant increase in the number of SPª²IR positive fibers in SO2 group (P<0.05 vs control group). CONCLUTION: Exposure to low concentration of SO2 would injure healthy rat airway, and one of its mechanisms is neurogenic inflammation that can exacerbates the response of airway inflammation. ......