Potassium permeability in the absence of fluid reabsorption in proximal tubule of the anesthetized rat

Experiments were performed to study the reabsorption of potassium in the surface proximal convoluted tubules (PCT) of kidneys from rats. The microperfusion method with rubidium-86 as transport marker was the selected technique. The factors considered in the potassium reabsorption were convection, diffusion and active transport. Results revealed that the permeability of the PCT was not dependent on the fluid reabsorption elimination. Potassium transport permeability was adequately evaluated through effective use of the rubidium-86 as a marker.