Biological activities of 24-fluoro-1 alpha,25-dihydroxyvitamin D-2 and its 24-epimer.
Biological activities of two epimeric 24-fluorinated vitamin D-2 analogs, 24-fluoro-1 alpha,25-dihydroxyvitamin D-2 [24-F-1,25-(OH)2D2] and its 24-epimer [24-epi-24-F-1,25-(OH)2D2], were studied and compared with 1 alpha,25-dihydroxyvitamin D-3 [1,25-(OH)2D3] and 1 alpha,25-dihydroxyvitamin D-2 [1,25-(OH)2D2]. 24-F-1,25-(OH)2D2 was nearly as active as 1,25-(OH)2D3 and 1,25-(OH)2D2 both in regulating calcium metabolism in vivo including bone mineral mobilization and intestinal calcium transport and in inducing differentiation of HL-60 cells. While 24-epi-24-F-1,25-(OH)2D2 showed distinct properties in these two types of the actions. Though the 24-epimer was nearly as potent as 1,25-(OH)2D3 in inducing differentiation of HL-60 cells, it showed little activity in regulating calcium metabolism in vivo. The fluorine atom introduced at the 24-position of either 1,25-(OH)2D2 or its 24-epimer had no potentiating effect. This is in sharp contrast with the cases of 24- and 26,27-multifluorinated analogs of active vitamin D-3.
Imae
Y
Y
Research Laboratories of Biological Science, Kodama Ltd., Chiba, Japan.
Manaka
A
A
Yoshida
N
N
Ishimi
Y
Y
Shinki
T
T
Abe
E
E
Suda
T
T
Konno
K
K
Takayama
H
H
Yamada
S
S
D000818:Animals; D001692:Biological Transport; D001862:Bone Resorption; D002118:Calcium / Q000097:blood / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D004872:Ergocalciferols / Q000138:chemical synthesis* / Q000378:metabolism; D006801:Humans; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism; D014407:Tumor Cells, Cultured
D004872:Ergocalciferols; C088762:24-fluoro-1,25-dihydroxyvitamin D2; D002118:Calcium