Expression of the epithelial Na(+) channel and other components of an aldosterone response pathway in human adrenocortical cells.

We have unexpectedly found expression of the epithelial Na(+) channel (ENaC) in human adrenocortical cells and tested the hypothesis that these cells contain the components of an aldosterone response pathway. Tissue was obtained from patients undergoing adrenalectomy and mRNA and protein expression of recognised components of an aldosterone-response pathway were determined by RT-PCR and Western blotting. The effects of mineralocorticoid receptor agonists and antagonists, amiloride analogues, and extracellular Na(+) on basal and stimulated aldosterone release from immortalised (H295R) cells were determined by radioimmunoassay.