FIGURE 2.

Smoke inhalation reduces pancreatic fluid and bicarbonate secretion and inhibits cystic fibrosis transmembrane conductance regulator (CFTR) Cl^– channel expression and function. (A and B) A six‐week period of smoke inhalation caused significantly reduced forskolin‐stimulated in vitro (A) and secretin‐stimulated in vivo (B) fluid secretion of isolated guinea pig pancreatic ducts. (C) Alkalisation of intracellular pH (pH_i) caused by luminal Cl^– removal from the extracellular solution was significantly lower in isolated ducts from the smoke‐exposed animals (n = 17) compared to the control (n = 11), suggesting that HCO₃ ^– secretion is reduced by smoking. L: luminal side; B: basal side. (D) The whole‐cell configuration of the patch clamp technique demonstrated that whole‐body smoke exposure significantly reduced the forskolin‐stimulated Cl^– current of CFTR in smoking guinea pig pancreas ductal epithelial cells (n = 4−5). (E–G) Confocal images indicated that the apical plasma membrane expression of CFTR was significantly decreased in guinea pig pancreatic ducts exposed to whole‐body smoke (F) compared to the control (E). (G) No‐primary antibody control. Green: CFTR; blue: DAPI. Scale bar = 50 µm. (H) Intensity profile of CFTR localisation confirmed that apical distribution was impaired because of the effect of smoking (n = 9−14). Exact p‐values are indicated above each column.