Regulation by calcium of the synthesis of 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 in Walker 256 carcinosarcoma cells:: comparison with synthesis regulation from renal phenotype cells (LLC-PK1)

The aim of this work was to study the regulation by calcium of the synthesis of 1,25-dihydroxyvitamin D-3 (1,25(OH)(2)D-3) and 24,25-dihydroxyvitamin D-3 (24,25(OH)(2)D-3) in Walker 256 carcinosarcoma (W-256) cells compared to renal phenotype LLC-PK1 cells. We have detected synthesis of 1,25(OH)(2)D-3 and 24,25(OH)(2)D-3 in W-256 cells. Levels of 1,25(OH)(2)D-3 in W-256 were similar to those of LLC-PK1 cells. Levels of 24,25(OH)(2)D-3 were higher in W-256 than in LLC-PK1 cells. High levels of calcium inhibited 1,25(OH)(2)D-3 synthesis in LLC-PK1 cells but not in W-256 cells. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.