Phagocytic cells metabolize 25‐hydroxyvitamin D₃ to 10‐oxo‐19‐nor‐25‐hydroxyvitamin D₃ and a new metabolite, 8α,25‐dihydroxy‐9, 10‐seco‐4,6,10(19)‐cholestatrien‐3‐one

Abstract

The metabolism of 2Shydroxyvitamin DJ [25(OH)D,] was examined in several phagocytic cells including alveolar macrophages and myeloid leukemia cells (Ml, HL-60 and U937). Phagocytic cells converted 25(OH)D, to D3 and a new metabolite. The former metabolite was dominant in shorter incubation periods (1 h), whereas the latter dominated over longer incubation periods (24 h). The new metabolite was produced from 25(OH)D, directly but not through lo-oxo-19-nor-25-hydroxyvitamin D3. The new metabolite was unequivocally identified as 8a,25-dihydroxy-9,10-seco-4,6,10( 19)~chole-statrien-3-one. These results suggest that phagocytic cells somehow promote oxidation of the triene part of vitamin D compounds.Vitamin D metabolism; Phagocytic cell; Macrophage; lo-0x0-l9-nor-25-hydroxyvitamin D3; 8a,25-Dihydroxy-9,1 O-seco-4,6,10( 19)-cholestatrien-3-one