Expression of 25-hydroxyvitamin D3-1alpha-hydroxylase along the nephron: new insights into renal vitamin D metabolism.
Renal synthesis of the active form of vitamin D, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], is a pivotal step in calcium and phosphate homeostasis. Production of 1,25(OH)2D3 is catalyzed by the mitchondrial cytochrome P450, 25-hydroxyvitamin D3-1alpha-hydroxylase (1alpha-HYD). As a consequence of the tight regulation of vitamin D metabolism during normal physiology, studies of the expression and regulation of 1alpha-HYD have proved remarkably difficult. However, the recent cloning of the gene for 1alpha-HYD has enabled a more comprehensive analysis of the tissue distribution of 1alpha-HYD, as well as the mechanisms involved in controlling 1,25(OH)2D3 production. In particular, an understanding of site-specific expression and regulation of 1alpha-HYD along the nephron might help to elucidate a more versatile role for 1,25(OH)2D3 in renal physiology.
Bland
R
R
Division of Medical Sciences, The University of Birmingham, UK.
Zehnder
D
D
Hewison
M
M
D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000378:metabolism*; D000818:Animals; D026541:Heymann Nephritis Antigenic Complex; D006801:Humans; D007668:Kidney / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000378:metabolism; D008954:Models, Biological; D008956:Models, Chemical; D009399:Nephrons / Q000201:enzymology*; D018167:Receptors, Calcitriol / Q000502:physiology; D014807:Vitamin D / Q000378:metabolism*; D014809:Vitamin D-Binding Protein / Q000378:metabolism
D026541:Heymann Nephritis Antigenic Complex; D008562:Membrane Glycoproteins; D018167:Receptors, Calcitriol; D014809:Vitamin D-Binding Protein; D014807:Vitamin D; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase