Titre du document / Document title

Regulation of rat ileal NHE3 by 1,25(OH)₂-Vitamin D₃

Auteur(s) / Author(s)

GILL R. ⁽¹⁾ ; NAZIR T. M. ⁽¹⁾ ; WALI R. ⁽²⁾ ; SITRIN T. M. ⁽²⁾ ; BRASITUS T. A. ⁽²⁾ ; RAMASWAMY K. ⁽¹⁾ ; DUDEJA P. K. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Medicine, University of Illinois at Chicago and VAMC Chicago (Westside), Chicago, Illinois 60612, ETATS-UNIS
⁽²⁾ University of Chicago, Chicago, Illinois 60637, ETATS-UNIS

Résumé / Abstract

We have previously demonstrated a modulation of Na⁺/H⁺ exchange (NHE) activity by vitamin D₃ in the rat ileum and Caco-2 cells. However, the molecular mechanism(s) of action of vitamin D₃ on NHE are still not understood. The current studies were undertaken to understand the regulation of individual NHE isoforms on mRNA levels in two distinct models of vitamin D₃ deficiency. Acute D₃ deficiency was induced secondary to streptozotocin-induced diabetes mellitus, while chronic D₃ deficiency was induced by feeding a D₃-deficient diet in an environment devoid of fluorescent light. Vitamin D₃ deficiency in both models increased the initial rates of rat ileal brush-border membrane (BBM) Na⁺/H⁺ exchange by 2.5-fold compared to D-repleted controls. In parallel to the increased exchanger activity, NHE3 mRNA abundance was increased about twofold in both acute and chronic D deficiency compared to control. There was no change in NHE1 or NHE2 abundance in vitamin D₃-deficient rat ileum. These findings indicate that vitamin D₃ regulates Na⁺/H⁺ exchange activity in rat ileum by influencing the mRNA levels of NHE3, the predominant luminal membrane isoform involved in vectorial Na⁺ transport.

Revue / Journal Title

Digestive diseases and sciences    ISSN  0163-2116   CODEN DDSCDJ 

Source / Source

2002, vol. 47, n^o5, pp. 1169-1174 (26 ref.)

Langue / Language

Anglais

Editeur / Publisher

Springer, Heidelberg, ALLEMAGNE  (1979) (Revue)

Mots-clés anglais / English Keywords

Vitamin

;

Electrolyte

;

Digestive diseases

;

Vertebrata

;

Mammalia

;

Rodentia

;

Rat

;

Animal

;

Colecalciferol

;

Deficiency

;

Regulation(control)

;

Hydrogen ion

;

Sodium

;

Ion exchange

;

Ileum

;

Mots-clés français / French Keywords

Vitamine

;

Electrolyte

;

Appareil digestif pathologie

;

Vertebrata

;

Mammalia

;

Rodentia

;

Rat

;

Animal

;

Colécalciférol

;

Déficit

;

Régulation

;

Hydrogène ion

;

Sodium

;

Echange ion

;

Iléon

;

Mots-clés espagnols / Spanish Keywords

Vitamina

;

Electrolito

;

Aparato digestivo patología

;

Vertebrata

;

Mammalia

;

Rodentia

;

Rata

;

Animal

;

Colecalciferol

;

Déficiencia

;

Regulación

;

Hidrógeno ión

;

Sodio

;

Cambio iónico

;

Ileon

;

Localisation / Location

INIST-CNRS, Cote INIST : 5060, 35400010818764.0320