LOCAL DEHYDROGENATION OF THE C11 HYDROXYL GROUP ON CORTISOL PROTECTS MINERALOCORTICOID RECEPTORS (MR)    
FROM INAPPROPRIATE ACTIVATION 
ALDOSTERONE:MR                                         Kd~1nM CORTISOL or CORTISONE : MR                     Kd~1nM
CORTISOL or CORTISONE : GR                     Kd~10nM
IN SPITE OF THE HIGH AFFINITY OF CORTISOL / CORTISONE FOR THE MR IN VITRO, GLUCOCORTICOIDS DO NOT BIND TO MR IN TARGET TISSUES.  THIS IS DUE TO THE ³PRE-RECEPTOR INACTIVATION² OF CORTISOL BY 11ß-HSD2
 
 
CORTISOL
GR
11ß-HSD1
CORTISOL
nucleus
 
CORTISOL
11ß-HSD2
CORTISONE
KIDNEY,COLON
SALIVARY
GLAND, HEART
LIVER
ADIPOSE
GONADS
OXIDATION OF
C11 HYDROXYL
nucleus
NO RESPONSE
MR
RESPONSE