24R,25‐Dihydroxyvitamin D stimulates creatine kinase BB activity in chick cartilage cells in culture

Abstract
In chick limb-bud cartilage cell cultures 24R,25-dihydroxycholecalciferol (24R,25(OH)2D3), but not 24S,25(OH)2D3, 1α,25(OH)2D3 or 25(OH)D3, stimulates the activity of the brain type (BB) isozyme of creatine kinase (EC 2.7.3.2), the ‘estrogen-induced protein’ first identified in rat uterus. Cultures treated with bromodeoxyuridine, in which cartilage formation in inhibited, show no stimulation of creatine kinase BB by 24R,25(OH)2D3.