Effect of glucose on the function of the calcitriol receptor and vitamin D metabolism.
Kidney Int
; 52(1): 79-86, 1997 Jul.
Article
em En
| MEDLINE
| ID: mdl-9211349
ABSTRACT
The genomic action of calcitriol is mediated through the interaction of the calcitriol receptor (VDR) with vitamin D response elements (VDREs) of the target genes. It has been proposed that chemicals capable of Schiff base formation with the VDR potentially could alter the physiological function of VDR and calcitriol metabolism. Since glucose has been shown to form Schiff bases with proteins, we tested the hypothesis that glucose could influence the function of VDR and thereby alter calcitriol metabolism. Glucose 6-phosphate inhibited VDR binding to the osteocalcin VDRE and chemically modified the DNA binding domain or the dimerization domain of the VDR in vitro. Further, glucose also blocked the production of chloramphenicol acetyltransferase (CAT) enzyme induced by calcitriol in cells transfected with a constructed VDRE attached to a CAT reporter gene. Hyperglycemia induced by glucose infusion or by streptozotocin in normal rats significantly reduced intestinal 1 alpha, 25-dihydroxyvitamin D-24-hydroxylase activity. Taken together, these findings are consistent with the hypothesis that glucose could interact with the VDR to impair its DNA binding and function within cells.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vitamina D
/
Receptores de Calcitriol
/
Sistema Enzimático do Citocromo P-450
/
Glucose
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Kidney Int
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos