Sodium transport across toad epithelia. Different responses of skin and urinary bladder to salinity adaptation.

Abstract

Short circuit current across abdominal skin and urinary bladder, were measured on epithelia taken from animals which were adapted to either distilled water or 400 mOsm NaCl. Syntocinon and Amiloride were used to achieve maximal stimulation and maximal inhibition respectively. The Amiloride-sensitive component of Na-transport, thus obtained, almost diminished in skin, but only 30% reduced in the urinary bladder from 400 mOsm adapted animals as compared to preparations from distilled water adapted animals. The differential response of the two epithelia is attributed to the regular moulting which is found for the skin but not with the bladder.