Binding of [3H]aldosterone to a single population of cells within the rat epididymis

Using the dry-mount autoradiographic technique, a single population of cells within the rat epididymis, the clear cells, have been shown to bind [3H]aldosterone at a nuclear site. Competitive binding experiments demonstrated that aldosterone was more potent than desoxycorticosterone than testosterone in reducing the nuclear uptake of radioactive aldosterone. Furthermore, the other epididymal cells (principal and basal cells) in all regions of the epididymis were not significantly labelled; occasional labelling was noted in some endothelial and stromal cells. It is suggested that aldosterone may play a role in controlling the intracellular and transcellular movement of ions and water necessary for concentrating absorbed macromolecules in the clear cell.