GLUCOCORTICOID RECEPTOR, MINERALOCORTICOID RECEPTORS, 11-BETA-HYDROXYSTEROID DEHYDROGENASE-1 AND DEHYDROGENASE-2 EXPRESSION IN RAT-BRAIN AND KIDNEY - IN-SITU STUDIES

In mammals, 11 beta-hydroxysteroid dehydrogenase (11-HSD) activity all ows aldosterone occupancy of mineralocorticoid receptors (MR) by inact ivating endogenous glucocorticoids. The present study examined the dis tribution of 11-HSD2, 11-HSD1, glucocorticoid receptor (GR) and MR in kidney and brain. High levels of expression of 11-HSD2 were found in r enal cortical distal tubules and more diffusely expressed in distal tu bules of the medulla. No expression of 11-HSD2 was found on serial sec tioning of the brain. 11-HSD1 was expressed in proximal tubules of the kidney and throughout the brain. GR mRNA was found predominantly in r enal proximal tubules and diffusely in brain, while MR mRNA was locate d 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.