Epidermal dexamethasone receptors in dogs with confirmed hyperadrenocorticalism, hypothyroidism or undiagnosed hormonal alopecia

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.