COPD Mucus Secretion Mechanism

Objectives To investigate the relationship of the human calcium-activated chloride channel 1 (CaCC₁) and mucus overproduction in the airway of Chinese patients with COPD, the expression of CaCC₁, MUC5AC and mucus in bronchial tissues were examined.Methods Bronchial tissues were isolated from non-cancerous areas of lungs obtained following resection for lung neoplasm in West China Hospital from April to July in 2004. 25 patients were diagnosed lung neoplasm with COPD, and other 20 were diagnosed lung neoplasm without COPD as the control subjects. The expression of CaCC₁, MUC5AC and mucin in bronchial tissues was detected by RT-PCR, in situ hybridization with DIG-labeled RNA probe, immunohistochemical and Alcian blue-periodic acid Schiff (AB-PAS) staining, respectively.Results Compared with the control group, a stronger expression of CaCC₁ was further detected throughout the bronchial tissues from patients with COPD (P=0.01). Furthermore, the stronger expressions of the CaCC₁ mRNA was related to the severity of airflow obstruction. Samples from COPD showed a stronger staining for MUC5AC than those in control subjects (P=0.01) and AB-PAS staining revealed more mucins in COPD patients'...