[Receptor-effector relations in the effect of adosterone on mononuclear leukocytes: validation and application to various water and electrolyte imbalances in humans].

Mineralocorticoid receptors were found in cells from extrarenal tissues such as spleen, hippocampus, smooth muscle, heart, hypophysis and mammary gland. Recently, mineralocorticoid receptors and effects of aldosterone on intracellular sodium and potassium have been described for human mononuclear leukocytes (HML). Both intracellular sodium and potassium concentrations decreased when HML from normal subjects were incubated for 1 h in a medium without aldosterone. In the presence of 1.4 nM aldosterone this loss of intracellular sodium and potassium from HML was absent, with values similar to those found in freshly prepared cells before incubation. The clinical significance of this model was underlined by the demonstration of absent or a decreased number of mineralocorticoid receptors and the lack of electrolyte response to aldosterone in HML of patients with pseudohypoaldosteronism. For patients with primary and secondary aldosteronism a reduced number of mineralocorticoid receptors has been shown on HML, thus indicating a "down-regulation" in response to chronically elevated serum levels of aldosterone. Additionally, an abnormal effector mechanism could be demonstrated in HML from these patients. These studies are the first to demonstrate the significance of extrarenal, nonepithelial mineralocorticoid receptors and the related effector mechanism for different disorders of the water- and electrolyte-balance in man.