Epidermal and hepatic glucocorticoid receptors in cats and dogs

Low capacity, high affinity ³H] dexamethasone binding receptors were identified in cytosolic preparations of liver (mean number 45±10·1 fmol mg⁻¹ protein, apparent dissociation constant 0·4±0·1 nM) and skin (mean number 46·4±23·8 fmol mg⁻¹ protein, apparent dissociation constant 1 ± 0·2 nM) of clinically normal dogs. For clinically normal cats, approximately half these numbers of receptors with a lower affinity, were detected in liver (mean number 23·1±10·4 fmol mg⁻¹ protein, apparent dissociation constant 3·2±0·9 nM) and skin (mean number 23·90±10·9 fmol mg⁻¹ protein, apparent dissociation constant 2·2±1·5 nM). This difference between dogs and cats in ³H] dexamethasone binding receptors may contribute to the relative glucocorticoid resistance observed in cats.