The effect of furosemide on acid secretion and Cl- transport was studied in isolated fundic mucosa of the guinea pig. Furosemide (10-3 M), applied to the serosal side produced an immediate effect on the short-circuit current (I(sc)), lowering it by 47 ± 2%. Potential difference decreased by 29 ± 3%, electrical conductance by 18 ± 4%, acid secretion by 38 ± 1%, and net flux of Cl- from serosal-to-mucosal side by 37%. Application of the drug to the mucosal side produced similar effects on acid secretion and on the electrical parameters. It is suggested that furosemide blocks the entrance of Cl-, by the Na+ - Cl- cotransport mechanism, through the basolateral membrane of the secreting cell. The consequent reduction in electrogenic Cl- transport would cause I(sc) and acid secretion to decrease. A reduction of Cl- conductance of the apical membrane, upon mucosal application of the drug, would cause similar effects on acid secretion and Cl- transport.
|Journal||American Journal of Physiology - Gastrointestinal and Liver Physiology|
|State||Published - 1980|