Coupling between chloride absorption and base excretion in isolated skin of Rana esculenta

Publisher Website
Google Scholar
Abstract
The net excretory fluxes of base (HCO3- or OH-) and the unidirectional fluxes of chloride were measured and their relationship examined in isolated frog [R. esculenta] skin maintained in open- or short-circuit (OC or SC) conditions. When the mucosal solution was a 2 mM choline chloride solution and the serosal solution a Ringer solution buffered with a HCO3-/CO2 mixture, the rate of base excretion was -105 .+-. 10 in OC and -60 .+-. 7 neq h-1 cm-2 in SC. A highly significant correlation was observed between influx of Cl and the excretion of base. As a function of external Cl concentration both these parameters followed saturation kinetics, Vmax being obtained for a Cl concentration below 2 mM. The removal of Cl in the external solution was followed by a 70 or 100% inhibition of base excretion in OC and SC conditions, respectively. Cl transport is dependent on the presence of a HCO3-/CO2 mixture in the internal or external medium. This transport, as well as base excretion, are inhibited to a considerable extent by removal of HCO3-/CO2 or by acetazolamide (10-3 M). This investigation characterizes a saturable transport system in which Cl absorption and base excretion are coupled.

This publication has 0 references indexed in Scilit: