Cultured rat growth plate chondrocytes express low levels of 1alpha-hydroxylase.
Growth plate chondrocytes are the target of the hydroxylated vitamin D metabolites 1alpha,25(OH)2D3 and 24,25(OH)2D3. Because studies on the production of these polar metabolites were inconclusive in various in vitro systems, the expression of a potential paracrine/autocrine vitamin D system was examined in primary cultures of rat growth plate chondrocytes using real-time RT-PCR. Compared to UMR cells and renal homogenates primary cultures of growth plate chondrocytes expressed low levels of 25-hydroxy-1alpha-hydroxylase as well as 25-hydroxy-24-hydroxylase. The expression of both is modulated by 25 vitamin D3, but 1alpha,25(OH)2D3 affected only 25-hydroxy-24-hydroxylase. If these findings are confirmed in intact growth plates, the polar vitamin D metabolites could act in a paracrine/autocrine fashion within the growth plate.
Weber
Lutz
L
Deptartment of Pediatrics, University of Marburg, Marburg, Germany.
Hügel
Ulrike
U
Reichrath
Jørg
J
Sieverts
Hauke
H
Mehls
Otto
O
Klaus
Günter
G
D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002117:Calcitriol / Q000031:analogs & derivatives / Q000494:pharmacology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000201:enzymology*; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006132:Growth Plate / Q000201:enzymology*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013250:Steroid Hydroxylases / Q000235:genetics / Q000378:metabolism*; D065668:Vitamin D3 24-Hydroxylase
D012333:RNA, Messenger; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D065668:Vitamin D3 24-Hydroxylase; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D002117:Calcitriol