Localization and vasopressin regulation of the Na+-K+-2Cl- cotransporter in the distal colonic epithelium

Figure 4 Apical Na⁺-K⁺-2Cl^- cotransporter involvement in the serosal vasopressin-induced I_SC response. A: Representative I_SC recordings in response to indomethacin (10 μmol, basolateral), TTX (tetrodotoxin, 1 μmol/L, basolateral), bumetanide (10 μmol/L, apical), and vasopressin (5 × 10^-8 mol/L, basolateral); B: Representative ISC recordings in response to indomethacin (10 μmol/L, basolateral), TTX (tetrodotoxin, 1 μmol/L basolateral), amiloride (10 μmol/L, apical), and vasopressin (5 × 10^-8 mol/L, basolateral). Arrows indicate the time of drug addiction; C: Representative I_SC recordings in response to indomethacin (10 μmol/L, basolateral), TTX (tetrodotoxin, 1 μmol/L, basolateral), TEA (5 mmol/L, apical), and vasopressin (5 × 10^-8 mol/L, basolateral); D: Comparison of the effects of serosal vasopressin on the I_SC with or without apical pretreatment with bumetanide (n = 9), amiloride (n = 6) and TEA (n = 6). Values are mean ± SE; ⁱP < 0.05; ^gP < 0.01.