Target Cells for 1,25-Dihydroxyvitamin D ₃ in Intestinal Tract, Stomach, Kidney, Skin, Pituitary, and Parathyroid

Abstract

After mature rats that had been fed on a vitamin D3-deficient diet were injected with tritium-labeled 1,25-dihydroxyvitamin D3, radioactivity became concentrated in nuclei of luminal and cryptal epithelium of the duodenum, jejunum, ileum, and colon; in nuclei of the epithelium of kidney distal tubules including the macula densa, and in podocytes of glomeruli; in nuclei of the epidermis including outer hairshafts and sebaceous glands; and in nuclei of certain cells of the stomach, anterior and posterior pituitary, and parathyroid. These results reveal cell types that contain receptors for 1,25-dihydroxyvitamin D3 or metabolites of this compound both in known or hypothesized target tissues and in tissues that were previously unknown to participate in vitamin D3 metabolism.

Physical and Functional Interaction between the Vitamin D Receptor and Hairless Corepressor, Two Proteins Required for Hair Cycling

“…Endogenous Hr and VDR Colocalize in Hair Follicles-VDR expression has been demonstrated in human and mouse skin, most intensely in hair root sheaths (57), keratinocytes (58), and the outer shaft of the hair follicle (59). Similarly, hr expression has been reported in hair follicles (including inner root sheath and matrix cells) and in the interfollicular epidermis (27,60).…”

Low Vitamin D and High Fibroblast Growth Factor 23 Serum Levels Associate with Infectious and Cardiac Deaths in the HEMO Study

“…[28][29][30][31] According to this paradigm, the availability of circulating 25(OH)D is essential for these organs to generate 1,25(OH) 2 D which subsequently acts in an autocrine or paracrine manner to serve their respective local needs. Thus, contrary to the kidney, the extrarenal production of 1,25(OH) 2 D does not contribute to the circulating pool of 1,25(OH) 2 D. 28 This might explain the association between circulating levels of 25(OH)D and outcomes but the lack of association between circulating levels of 1,25(OH) 2 D with clinical events in the present analysis.…”

Analysis of the vitamin D system in basal cell carcinomas (BCCs)

“…[1][2][3] This potent seco-steroid hormone acts via binding to a corresponding intranuclear receptor (VDR), present in target tissues. 4,5 VDR belongs to the superfamily of trans-acting transcriptional regulatory factors, which includes the steroid and thyroid hormone receptors as well as the retinoid-X receptors and retinoic acid receptors. [6][7][8] Keratinocytes express VDR, 1,9 whose natural ligand, calcitriol, inhibits proliferation and induces differentiation of cultured human keratinocytes in vitro.…”