Chloride transport in rabbit esophageal epithelial cells

Abstract

We investigated Cl Ϫ transport pathways in the apical and basolateral membranes of rabbit esophageal epithelial cells (EEC) using conventional and ion-selective microelectrodes. Intact sections of esophageal epithelium were mounted serosal or luminal side up in a modified Ussing chamber, where transepithelial potential difference and transepithelial resistance could be determined. Microelectrodes were used to measure intracellular Cl Ϫ activity (a i Cl ), basolateral or apical membrane potentials (V mBL or VmC), and the voltage divider ratio. When a basal cell was impaled, V mBL was Ϫ73 Ϯ 4.3 mV and a i Cl was 16.4 Ϯ 2.1 mM, which were similar in presence or absence of bicarbonate. Removal of serosal Cl . These results indicate that 1) in rabbit EEC, a i Cl is higher than equilibrium across apical and basolateral membranes, and this process is independent of bicarbonate; 2) the basolateral cell membrane possesses a conductive Cl Ϫ pathway sensitive to flufenamate; and 3) the apical membrane has limited permeability to Cl Ϫ

OEsophageal Ion Transport Mechanisms and Significance Under Pathological Conditions

“…As a result, the osmotic pressure in the lumen increases, which promotes the movement of water into the lumen ( Frizzell and Hanrahan, 2012 ). Oesophageal Cl – transport in the squamous epithelium and SMGs was mainly investigated by Abdulnour-Nakhoul et al (2002) ( Tables 1 , 2 ). Using isolated rabbit OE, they showed the presence of Cl – conductance at both the basolateral and the apical membrane of oesophageal epithelial cells (OECs) ( Abdulnour-Nakhoul et al, 2002 ).…”

“…Oesophageal Cl – transport in the squamous epithelium and SMGs was mainly investigated by Abdulnour-Nakhoul et al (2002) ( Tables 1 , 2 ). Using isolated rabbit OE, they showed the presence of Cl – conductance at both the basolateral and the apical membrane of oesophageal epithelial cells (OECs) ( Abdulnour-Nakhoul et al, 2002 ). The basolateral Cl – conductance was Ca 2+ -dependent and flufenamate-sensitive.…”