The Effect of Potassium Deficiency on the Reabsorption of Protein in the Renal Tubule of the Rat

Male Wistar rats were made potassium-deficient by feeding a diet low in potassium, while controls were pair-fed the same diet supplemented with potassium. Four weeks later 10 mg of T-1824 was injected into each rat. It was found that the characteristic granules which accumulate in the renal collecting tubule cells as a result of potassium deficiency were colored blue and that a diminished coloration of the convoluted tubule cells of the kidney was present. Quantitative measurements of the renal T-1824 content showed that it was decreased as a result of potassium deficiency. The daily rate of protein excretion was increased by the potassium deficiency. It is concluded that potassium deficiency decreases reabsorption of protein in the convoluted tubules of the kidney and that increased proteinuria thus results. Also, the granules which appear in renal collecting tubule cells as a result of potassium deficiency contain serum protein, which probably enters the cells from the tubular lumen.