Figure 4 .

Effect of 1 µM ethylisopropylamiloride (EIPA) on large conductance K⁺ channel activity in isolated surface cells from rat distal colon. (A) Summary of results from five cell attached patches of membrane from distal colonic surface cells isolated from K⁺ loaded animals (Na₂SO₄ solution in bath, K₂SO₄ solution in the pipette; V_com = 0 mV). *p<0.001 compared with the value before the addition of EIPA. (B) Uniform effect of EIPA on K⁺ channel activity at holding voltages between −60 and 40 mV (n = 3 patches). Error bars not shown were smaller than the symbols. Differences between the values before and after the addition of EIPA were highly significant (p<0.001) at each holding voltage.