DEMONSTRATION OF 1,25-DIHYDROXYVITAMIN D3RECEPTORS IN HUMAN SKIN BIOPSIES

Abstract

In this study we report the demonstration of receptors for 1,25-(OH)₂vitamin D₃ in fresh and cultured human skin. Cultured fibroblasts grown from infant foreskin exhibit a binding site which by Scatchard analysis has a K_d for [³H]l,25-(OH)₂D₃ of 0.2 nM and an N_max of 40 fmol/mg cytosol protein. On sucrose density gradients the receptor sediments at 3.2S. Receptors could also be identified in skin biopsies from adult patients when assayed either in fresh epidermis or cultured keratinocytes and dermal fibroblasts. The human receptors are similar to rodent receptors assessed in classical target organs such as intestine, bone and kidney. The finding that receptors can be measured in cultured human skin after several serial passages indicates that skin biopsy may provide a means of assessing the 1,25-(OH)₂D₃ receptor status of patients.