Figure 2
From: Predominant constitutive CFTR conductance in small airways
Effect of amiloride and Forskolin (Fsk, 5 μM) + IBMX (100 μM) on transepithelial potential (TEP) of bronchiole. In the presence of luminal Cl-, the effects of both amiloride and Fsk+IBMX on TEP were almost imperceptible (left side). However, when Cl- was substituted with Gluconate to more effectively reveal the Cl- conductance, addition of amiloride depolarized TEP and Fsk+IBMX hyperpolarized the TEP (right side), suggesting that the large Cl- conductance present in the epithelium mutes (shunts) the smaller changes in conductance occasioned by amiloride and Fsk when isotonic Cl- is present bilaterally. NaGlu: Na-gluconate