Glucocorticoid receptor, mineralocorticoid receptors, 11 beta-hydroxysteroid dehydrogenase-1 and -2 expression in rat brain and kidney: in situ studies.

In mammals, 11 beta-hydroxysteroid dehydrogenase (11-HSD) activity allows aldosterone occupancy of mineralocorticoid receptors (MR) by inactivating endogenous glucocorticoids. The present study examined the distribution of 11-HSD2, 11-HSD1, glucocorticoid receptor (GR) and MR in kidney and brain. High levels of expression of 11-HSD2 were found in renal cortical distal tubules and more diffusely expressed in distal tubules of the medulla. No expression of 11-HSD2 was found on serial sectioning of the brain. 11-HSD1 was expressed in proximal tubules of the kidney and throughout the brain. GR mRNA was found predominantly in renal proximal tubules and diffusely in brain, while MR mRNA was located in the renal distal tubules and also in various brain nuclei. These anatomical findings support a functional relationship between 11-HSD1 and GR in both brain and kidney, but between 11-HSD2 and MR in kidney only.