INTERACTION BETWEEN NA IONS AND THE CL HCO3 EXCHANGER IN BASOLATERAL MEMBRANES FROM RAT JEJUNUM/

The jejunal basolateral Cl/HCO3 exchanger is modulated by two Na-depen dent regulatory sites located on the inner and outer membrane surfaces . The aim of this work was to focus on the interaction between the ani on exchanger and intracellular or extracellular sodium. Uptake studies , performed using basolateral membrane vesicles, provided kinetic para meters as a function of outside or inside Na concentration. The intrac ellular Na-sensitive modifier site seems to be primarily involved in t he modulation of the Cl/HCO3 exchanger.