fludrocortisone-acetate and Hyperaldosteronism

Primary aldosteronism is caused by bilateral idiopathic hyperplasia in approximately two-thirds of cases and aldosterone-producing adenoma in one-third. Most patients with primary aldosteronism are normokalemic. In the clinical setting of normokalemic hypertension, patients who have resistant hypertension and hypertensive patients with a family history atypical for polygenic hypertension should be tested for primary aldosteronism. The ratio of plasma aldosterone concentration to plasma renin activity has been generally accepted as a first-line case-finding test. If a patient has an increased ratio, autonomous aldosterone production must be confirmed with an aldosterone suppression test. Once primary aldosteronism is confirmed, the subtype needs to be determined to guide treatment. The initial test in subtype evaluation is CT imaging of the adrenal glands. If surgical treatment is considered, adrenal vein sampling is the most accurate method for distinguishing between unilateral and bilateral adrenal aldosterone production. Optimal treatment for aldosterone-producing adenoma or unilateral hyperplasia is unilateral laparoscopic adrenalectomy. The idiopathic bilateral hyperplasia and glucocorticoid-remediable aldosteronism subtypes should be treated pharmacologically. All patients treated pharmacologically should receive a mineralocorticoid receptor antagonist, a drug type that has been shown to block the toxic effects of aldosterone on nonepithelial tissues.

Topics: Adenoma; Adrenal Gland Neoplasms; Adrenal Glands; Adrenalectomy; Aldosterone; Algorithms; Animals; Antihypertensive Agents; Captopril; Fludrocortisone; Humans; Hyperaldosteronism; Hypokalemia; Mineralocorticoid Receptor Antagonists; Renin; Tomography, X-Ray Computed

Prostasin is a serine peptidase hypothesized to regulate epithelial sodium channel (ENaC) activity in animals or on in vitro cultured cells. We investigated whether urinary prostasin may be a candidate marker of ENaC activation in humans. We studied 10 healthy volunteers and 8 hypertensive patients with raised aldosterone-to-renin ratio before and after spironolactone or saline/Florinef suppression test, respectively. Four healthy subjects were also studied before and after saline. Urinary prostasin was evaluated by SDS-PAGE, 2D maps, and Western blotting. Every sample of normotensive individuals was compared with the corresponding sample of urine collected after spironolactone or saline; every sample of hypertensive patients was compared with the corresponding sample of urine collected after saline or Florinef. Prostasin was detectable in all subjects regardless of gender, dietary sodium intake, and spironolactone treatment. Spironolactone (100 mg) increased urinary Na+/K+ ratio and decreased urinary prostasin in normotensives in whom the renin/aldosterone axis was activated by a low Na+ intake, but it was ineffective in individuals with high Na+ intake. Saline infusion also reduced prostasin in normotensive subjects. In contrast, prostasin paradoxically increased in urine of patients affected by primary aldosteronism after volume expansion. By 2D immunoblotting, several protein isoforms were observed, some of them being overexpressed after inhibition tests in patients with primary aldosteronism. In addition to a "basal" aliquot of prostasin, constitutively released in human urine regardless of sodium balance and aldosterone activation, there exists a second "aldosterone-responsive" aliquot modulated by Na+ intake and potentially suitable as candidate marker of ENaC activation.

Topics: Adult; Aged; Aldosterone; Biomarkers; Blotting, Western; Case-Control Studies; Diuretics; Dose-Response Relationship, Drug; Epithelial Sodium Channels; Female; Fludrocortisone; Humans; Hyperaldosteronism; Hypertension; Male; Middle Aged; Potassium; Renin; Serine Endopeptidases; Sodium; Sodium Channels; Sodium Chloride; Sodium, Dietary; Spironolactone

It is known that some patients with primary aldosteronism show postoperative hyperkalemia, which is due to inability of the adrenal gland to secrete sufficient amounts of aldosterone. However, hyperkalemia is generally neither severe nor prolonged, in which replacement therapy with mineralocorticoid is seldom necessary. We report a case of a 46-year-old woman with an aldosterone-producing adenoma associated with severe postoperative hyperkalemia. After unilateral adrenalectomy, the patient showed episodes of severe hyperkalemia for four months, which required not only cation-exchange resin, but also mineralocorticoid replacement. Plasma aldosterone concentration (PAC) was low, although PAC was increased after rapid ACTH test. Histological examination indicated the presence of adrenocortical tumor and paradoxical hyperplasia of zona glomerulosa in the adjacent adrenal. Immunohistochemistry demonstrated that the enzymes involved in aldosterone synthesis, such as cholesterol side chain cleavage (P-450scc), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), and 21-hydroxylase (P-450c21), or the enzyme involved in glucocorticoid synthesis, 11beta-hydroxylase (P-450c11beta), were expressed in the tumor, but they were completely absent in zona glomerulosa of the adjacent adrenal. These findings were consistent with the patterns of primary aldosteronism. Serum potassium level was gradually decreased with concomitant increase in PAC. These results suggest that severe postoperative hyperkalemia of the present case was attributable to severe suppression of aldosterone synthesis in the adjacent and contralateral adrenal, which resulted in slow recovery of aldosterone secretion. It is plausible that aldosterone synthesis of adjacent and contralateral adrenal glands is severely impaired in some cases with primary aldosteronism, as glucocorticoid synthesis in Cushing syndrome.

Topics: Adenoma; Adrenal Gland Neoplasms; Adrenalectomy; Aldosterone; Female; Fludrocortisone; Humans; Hyperaldosteronism; Hyperkalemia; Immunoenzyme Techniques; Middle Aged; Potassium; Steroid Hydroxylases