Fig. 4
a A typical case showing the decrease in MQAE fluorescence intensity induced by leakage. The airway ciliary cells were treated with NPPB (20 µM), a Cl− channels blocker, to increase cell volume under the iso-osmotic condition. The addition of NPPB immediately decreased MQAE fluorescence intensity, which reached a plateau within 5 min. However, 15 min after the plateau had been reached, MQAE fluorescence intensity suddenly decreased. This sudden decrease in MQAE fluorescence intensity started at 22 min after addition of the NPPB addition. b Cell swelling induced by NPPB. The addition of NPPB immediately caused an increase and plateau in cell volume (V/V0). No further cell swelling was occurred during NPPB addition