ION-TRANSPORT ACROSS THE ISOLATED INTESTINAL-MUCOSA OF ANGUILLA-ANGUILLA (PISCES)

The posterior intestine of freshwater-adapted Anguilla anguilla has a serosa negative transepithelial potential difference (TPD), and a current corresponding to the bow of negative current towards serosa. The TPD and the short-circuit current (SCC) were inhibited by Na+ and K+ withdrawal, and Cl- substitution or BA(2+) addition inverts TPD and SCC, suggesting a Cl- and Na+ current mucosa-serosa, a K+-Cl- cotransport and a K+ channel in the mucosal side. The TPD and SCC were inhibited by ouabain, DIDS, furosemide and amiloride, indicating the presence of a Na+-K+-ATPase, and Cl-/HCO3-, Na+-K+-Cl- and Na+/H+ cotransporters.