Effect of exogenous adrenocortical hormones and states of adrenal dysfunction on body sodium and potassium composition.

Abstract

Large doses of hydrocortisonc, administered intravenously over a 32-hour period, had no acute effect on the exchangeability of body sodium and potassium in a normal female subject. Similarly administered desoxycorticosterone glucoside, however, had an acute effect (about a 14 per cent decrease) on the exchangeability of body sodium and potassium in another normal female subject. Data are presented from 4 studies which demonstrated that changes in body electrolyte status as measured by the classic metabolic balance technique were usually in good agreement with the changes as measured by the levels of exchangeable body sodium and potassium during prolonged (two weeks) administration of hydrocortisone (orally), ACTH-gel (intramuscularly), or desoxycorticosterone (intramuscularly). Discrepancies in results obtained by the 2 techniques arose frequently enough, however, to suggest the possibility that during prolonged administration of adrenal steroids or ACTH some of the retained sodium may be deposited in nonexchangeable stores, and that the nonexchangeable body potassium stores may become exchangeable during the potassium diuresis associated with prolonged hydrocortisone therapy. Nevertheless, such occasional discrepancies may be methodologic in origin. Body electrolyte measurements in 5 patients with Cushing's syndrome revealed in most instances a normal exchangeable body sodium content (Nae/Kg), a low exchangeable body potassium content (Ke/Kg), and correspondingly high Nae/Ke ratios. After bilateral adrenalectomy, the body potassium values and the Nae/Ke ratios returned slowly to normal after intervals of four to twelve months. Body electrolyte measurements in 2 masculinized females—1 with male, and 1 with female physique—showed good correlation with body habitus. Exchangeable body sodium and potassium values were within the wide normal range in 5 cases of treated Addison's disease. In 1 case of previously untreated Addison's disease the exchangeable body sodium and potassium values were normal, though the Nae/Ke ratio was slightly elevated (1.02). After two weeks of therapy with large doses of 9α-fluorohydrocortisone, the ratio was 1.51. After seven more weeks of therapy with reduced dosage, the ratio had returned to approximately the pre-treatment value. At the end of fourteen months of therapy the ratio was 1.06, but the Nae/Kg, and Ke/Kg. values were lower than before treatment, probably due to the patient's gain in electrolytepoor adipose tissue.