Directional instability and oscillation of the acid-base transport system of the tortoise urinary bladder, Damonia subtrijuga

1. 1. The urinary bladder of the tortoise, Damonia subtrijuga, transported Na+ from mucosa to serosa, H+ from serosa to mucosa, and base from mucosa to serosa. 2. 2. The acid-base transporting system sometimes became unstable, reversing direction, moving acid or base across both bladder surfaces simultaneously, or showing oscillations of the pH of the mucosal bathing medium. These instabilities in the acid-base transporting system were without effect on the polarity of the Na+ transporting system. 3. 3. Factors that stimulated (betazole) or inhibited (acetazolamide) acid-base transport did so whether the polarity of such transport was normal, or was reversed.