FIGURE 9.

Testing electrostatic effects created by positively charged MTS after reaction with I66C. A, measurements of Ca²⁺ permeability (P_Ca) of control and MTSET-treated cells, grown on Transwell filters, by tracer flux experiments (n = 4). B, to unmask surface charge effects, the dependence of conductance on ionic strength was determined in Ussing chambers. The NaCl activity of the medium of control and MTSEA-treated cells was gradually increased from 0 to 90 mm, replacing with mannitol as needed to maintain osmolality (n = 3). ***, p < 0.001, compared with control.