Sweat gland epithelial and myoepithelial cells are vitamin D targets

Nuclear receptor binding of 1,25(OH)(2)-vitamin D-3 (vitamin D) in skin keratinocytes of epidermis, hair sheaths and sebaceous glands was discovered through receptor microscopic autoradiography. Extended experiments with H-3-1,25(OH)(2)-vitamin D-3 and its analog H-3-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.