In anuric dogs K loaded by infusion of 2 meq of KCl/kg per h the quantity of K transferred to intracellular fluid in ureter-ligated animals is considerably less than in nephrectomized animals. The combination of ureter ligation and hyperkalemia seems to suppress transmembrane K transfer. Treatment of K loaded ureter-ligated dogs with epinephrine markedly increased the animals'' ability to transfer K to intracellular fluid. Administration of propranolol (with and without epinephrine) reduced K transfer capacity below the control level. Propranolol treatment of K-loaded nephrectomized dogs produced a striking diminution of K transfer ability. Apparently .beta.-adrenergic receptors are important in the transmembrane K transfer of K-loaded anuric dogs, and ureter ligation and hyperkalemia suppress K transfer capacity by blocking .beta.-receptors.