THE CONCENTRATION of sodium and chloride in sweat is greatly elevated in conditions of chronic deficiency of adrenal secretions, for example, Addison's disease in man.1 When the adrenals are removed experimentally in animals,2 or adrenal hormone therapy is withdrawn abruptly from patients with deficient adrenal function,3 characteristic alterations in renal excretion of electrolytes occur promptly. In these circumstances, the electrolyte excretion in sweat and urine is restored to normal quickly by aldosterone.4
In another disease, cystic fibrosis, the electrolyte content of sweat is regularly as high or higher than the levels found in chronic adrenal deficiency, but the secretion of aldosterone and renal control of electrolytes are normal in cystic fibrosis; furthermore, administration of aldosterone will not restore the electrolytes in sweat to normal in this disorder.5,6
This dissociation between sweat glands and kidneys in electrolyte regulation in cystic fibrosis (in contrast to their concomitant