Influences of interleukin 4 and interleukin 6 on the amiloride-sensitive Na~+ channel current in human bronchial epithelium cells of COPD patients

AIM: To investigate the amiloride-sensitive Na~+ channel current (Iamil) in primary cultured human bronchial epithelium cells of chronic obstructive pulmonary disease (COPD) patients and the influence of interleukin 4 and interleukin 6. METHODS: Human bronchial epithelium cells were isolated and cultured from 18 patients undergone pueumonectomy in hospital. Interleukin 4 or interleukin 6 at concentration of 10 μg/L was used to treat these cultured cells, and Iamil was measured by whole cell patch clamp techniques. RESULTS: There was no markedly difference among normal no-smoking group, normal smoking group and COPD group. Interleukin 4 down-regulated the Iamil in normal no-smoking group, normal smoking group and COPD group. The down-regulated percentages were 59.7%, 54.7% and 30.0%. Interleukin 4 down-regulated the Iamil in normal no-smoking group (44.8%) and normal smoking group (34.9%) but not in COPD group, and the current forms were not changed after IL-4 or IL-6 treatment. CONCLUSIONS: Interleukin 4 and interleukin 6 down-regulated the Iamil in primary cultured human bronchial epithelium cells. It may contribute to the hypersecretion of COPD, and the up-regulated interleukin 4 and interleukin 6 in COPD patients may cause them react weaker to the treatment of interleukin 4 and interleukin 6.