Characterization and quantification of epidermal and dermal glucocorticoid receptors in the rat.

The interaction between [3H]triamcinolone acetonide and cytosol proteins was studied in separated epidermis and dermis of neonatal rats. Both tissues possessed a binding site with a high affinity (dissociation constant = 0.2 nM) and a low capacity (150-220 fmol/mg protein) for triamcinolone acetonide. The binding site in each tissue cytosol was inactivated by heating at 37 degrees C or by incubating with either trypsin, Triton X-100 or NaCl. The second-order rate constant of association was 1.99 X 10(6)M-1min-1 for the epidermal, and 1.65 X 10(6)M-1min-1 for the dermal receptor binding site. Quantitatively there was a difference between the two tissues with 82% of the receptor being found in the dermis and 18% in the epidermis.