A study of [3H]aldosterone binding by nuclear and cytoplasmic receptors of the rat kidney with different content of aldosterone in the organism.
The distribution of specific mineralocorticoid receptors in rat kidney cells was found to depend on aldosterone concentration. With increasing aldosterone concentrations the number of specific receptors for aldosterone in the cytoplasm decreased and their quantity in the nuclei increased. This was evidently due to their enhanced transport from the cytoplasm to the nuclei. It was found that aldosterone (its complex with the receptor) attached to non-histone proteins of chromatin and that the structural integrity of DNA is needed to provide the binding of this complex to the cell nuclei. The quantity of aldosterone acceptor sites in the kidney cell nuclei remained constant when aldosterone concentrations in the organism changed, and, hence, the functional states of the target organ changed too.