Figure 8.

The effects of blocking barium-sensitive K⁺ channels on both sides by adding 1-mM BaCl₂ to the extracellular fluid (n = 8). The arrows show the time point where a new bath solution was applied to the bath or when the barium-sensitive K⁺ channel blocker BaCl₂ was added to the bath solution. (A) The I_SC as a function of time before and after the apical and basolateral application of BaCl₂ (1 mM) and 30 minutes later the change to low K⁺ Krebs solution (0-mM K⁺ concentration) with BaCl₂ (1 mM). The ordinate shows the measured value of the I_SC (in µA/cm²), and the red line is the control regression line calculated between the last three I_SC measurements of the control period at the beginning and the last three I_SC measurements of the control period at the end of the experiment. (B) TER as a function of time before and after the apical and basolateral application of BaCl₂ and the change of normal Krebs solution to low K⁺ Krebs solution with BaCl₂ (1 mM). The ordinate shows the measured value of TER (in ohm·cm²), and the red line is the control regression line, as in A.