OBJECTIVES: I. Establish the sodium and potassium intake that will maintain a normovolemic state in a patient with pseudohypoaldosteronism. II. Determine the effect of extracellular fluid volume and serum potassium manipulations on exercise tolerance, cardiac function, and endurance. III. Investigate pharmacologic methods of limiting excretion of sodium in urine and sweat.

PROTOCOL OUTLINE: Sodium and potassium intake resulting in normalization of serum electrolytes and markers of extracellular volume are determined at baseline. A trial diet is then prescribed, with adjustments made to achieve a steady state with normal serum electrolytes. Exercise tolerance and muscle function are evaluated at steady state. Sodium and potassium are sequentially manipulated with diet, enalapril, and polystyrene sulfonate. Exercise tolerance is evaluated during each diet period. A treatment plan to maintain electrolyte balance is developed. The patient is followed monthly for 3 to 6 months, then every 3 months for up to 3 years.

Genders Eligible for Study:  Both

Criteria