Sweat gland epithelial and myoepithelial cells are vitamin D targets

: Nuclear receptor binding of 1,25(OH)2‐vitamin D3 (vitamin D) in skin keratinocytes of epidermis, hair sheaths and sebaceous glands was discovered through receptor microscopic autoradiography. Extended experiments with 3H‐1,25(OH)2‐vitamin D3 and its analog 3H‐oxacalcitriol (OCT) now demonstrate nuclear receptor binding in sweat gland epithelium of secretory coils and ducts as well as in myoepithelial cells, as studied in paws of nude mice after i.v. injection. The results suggest genomic regulation of cell proliferation and differentiation, as well as of secretory and excretory functions, indicating potential therapies for impaired secretion as in hypohidrosis of aged and diseased skin.