Induction of reverse flow of Na+ through the active transport pathway in toad urinary bladder

Abstract When active Na + transport across the toad urinary bladder was abolished by ouabain, a ’reversed‘ short circuit current could be induced by an Na + concentration gradient. This reversed current was increased by vasopressin and inhibited by amiloride and appears to represent net Na + movement ‘backwards’ through epithelial cells which normally participate in active Na + transport across the bladder.