Mineralocorticoid receptors in rat anterior pituitary: toward a redefinition of "mineralocorticoid hormone".

There is increasing evidence that a pituitary factor(s) in addition to ACTH can influence aldosterone secretion. By analogy with glucocorticoids and ACTH, such a factor(s) may be under mineralocorticoid negative feedback control, presumably via specific mineralocorticoid receptors. We here report studies in which mineralocorticoid receptors in the anterior pituitary are described and clearly distinguished from glucocorticoid receptors. Pituitary mineralocorticoid receptors closely resemble those previously reported in rat kidney and salivary gland in terms of their affinity for aldosterone, the hierarchy of affinities they display for other steroids, and their sedimentation values on sucrose density gradients.