[Action of 1,25-dihydroxyvitamin D3 in the tooth germ. Modulations of receptor in the development].
The control of tooth development by 1,25-Dihydroxyvitamin D3 is analyzed by light- and electron-microscope immunocytochemistry and Northern-blotting in vitamin D-deficient rats. The receptor for 1,25-Dihydroxyvitamin D3, immunostained at the light microscope in all stem-cells, became immunodetectable only at the ultrastructural level in the ameloblasts which elaborate enamel and odontoblasts which synthetize dentin. Moreover, 1,25-Dihydroxyvitamin D3 induces an up-regulation specifically in these cells. In parallel, the calbindins-D9k, -D28k and osteocalcin, in contrast to the phosphoprotein, appear sensitive to vitamin D-deficiency. A single injection of 1,25-Dihydroxyvitamin D3 led to the increase of steady-state levels of the corresponding calbindin mRNAs. These data show that tooth constitutes a target-organ for 1,25-Dihydroxyvitamin D3, as other components of the phospho-calcic metabolism.
Hotton
D
D
INSERM U120, Hôpital Robert-Debré, Paris.
Davideau
J L
JL
Dupret
J M
JM
Pike
J W
JW
Mathieu
H
H
Berdal
A
A
D000818:Animals; D064026:Calbindins; D002454:Cell Differentiation / Q000187:drug effects; D004100:Dihydroxycholecalciferols / Q000494:pharmacology*; D008297:Male; D015675:Osteocalcin / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D011987:Receptors, Steroid / Q000032:analysis*; D064030:S100 Calcium Binding Protein G / Q000032:analysis; D014083:Tooth Germ / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
D064026:Calbindins; D004100:Dihydroxycholecalciferols; D011987:Receptors, Steroid; D064030:S100 Calcium Binding Protein G; D015675:Osteocalcin
Action de la 1,25-dihydroxyvitamine D3 dans le germe dentaire. Modulations du récepteur au cours du développement.