Demonstration of 1,25-dihydroxyvitamin D3 receptors in human skin biopsies.

In this study we report the demonstration of receptors for 1,25-(OH)2 vitamin D3 in fresh and cultured human skin. Cultured fibroblasts grown from infant foreskin exhibit a binding site which by Scatchard analysis had a Kd for [3H]1,25-(OH)2D3 of 0.2 nM and an Nmax of approximately 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 findings that receptors can be measured in cultured human skin after several arterial passages indicates that skin biopsy may provide a means of assessing the 1,25-(OH)2D3 receptor status of patients.