Isolation and Characterization of the Estrogen Receptor in Human Skin*

Abstract

Evidence exists which suggests that skin is a target tissue for several steroid hormones. However, the receptors for certain steroids, e.g. estrogens, have not been demonstrated in human skin. Evidence is presented which identifies and characterizes an estrogen receptor in normal human skin. Fresh surgical specimens of normal face skin were stripped of excess sc tissue and used immediately. The skin was homogenized in 2 ml buffer/tissue with a Brinkmann Polytron homogenizer, and the homogenate was centrifuged for 10 min at 10⁴ × g. This supernatant was again centrifuged for 1 h at 10⁵ × g to obtain the cytosol. When this cytosol was incubated with [³H]estradiol, a specific binding protein for the steroid was detected. This binding protein displayed 1) a high affinity for estrogen (K_d ≃ 1.5 × 10^-10 M), 2) steroid specificity, 3) tissue specificity, 4) a precipitation in a 40% saturated solution of ammonium sulfate, 5) a sedimentation value of 3S in sucrose gradients using high ionic conditions, and 6) two molecular species focusing at pH 5.9 and 7.5, respectively. Skin specimens from different regions of the body displayed marked differences in the levels of receptor. The skin from the face demonstrated much greater concentrations of receptor than thigh or breast skin. Since certain dermatological conditions indicate an abnormal response by skin target cells to estrogen, comparisons of the estrogen receptors of normal and diseased skin with respect to the above parameters can now be made.