title: Biological activity of 24,24-difluoro-1,25-dihydroxyvitamin D3.
abstract: The biological activity of 24,24-difluoro-1,25-dihydroxyvitamin D3 was compared with 1,25-dihydroxyvitamin D3 in the rat. The 24,24-difluoro-1,25-dihydroxyvitamin D3 has a potency of approximately 5-10 times that of 1,25-dihydroxyvitamin D3 in the known in vivo vitamin D responsive systems. These systems include intestinal calcium transport, bone calcium mobilization, calcification of epiphyseal plate cartilage, and elevation of plasma calcium and phosphorus concentrations. Thus, 24,24-difluoro-1,25-dihydroxyvitamin D3 is the first known analogue with higher potency than 1,25-dihydroxyvitamin D3 in vivo.
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002118:Calcium / Q000097:blood / Q000378:metabolism*; D004386:Duodenum / Q000378:metabolism; D007408:Intestinal Absorption / Q000187:drug effects; D007413:Intestinal Mucosa / Q000378:metabolism; D007700:Kinetics; D008297:Male; D010710:Phosphates / Q000097:blood; D051381:Rats; D013329:Structure-Activity Relationship; D014808:Vitamin D Deficiency / Q000378:metabolism
chemical_list: D010710:Phosphates; C023370:24,24-difluoro-1,25-dihydroxyvitamin D3; D002117:Calcitriol; D002118:Calcium