Glucocorticoid binding sites in human temporal cortex.

This work describes the presence of glucocorticoid binding sites in human temporal cortex obtained following partial lobectomy in two epileptic patients. Using [3H]dexamethasone as radioligand and cold cortisol or RU 28362 as competitor we found an apparent Kd of approximately 2.8 nM with a Bmax of approximately 34 fmol/mg protein. The order of potency of various unlabeled steroids to compete for [3H]dexamethasone binding was as follows: RU 28362 = RU 38486 = cortisol = dexamethasone greater than progesterone greater than spironolactone greater than estradiol. These data provide evidence for an intracellular mechanism by which circulating glucocorticoids might regulate neuronal function in the human cortex.