Dietary sulfate regulates the expression of the renal brush border Na/Si cotransporter NaSi-1.
J Am Soc Nephrol
; 9(9): 1568-73, 1998 Sep.
Article
de En
| MEDLINE
| ID: mdl-9727363
ABSTRACT
Dietary inorganic sulfate (Si) intake is an important factor in the regulation of renal proximal tubular sodium-dependent Si transport (Na/Si cotransport). The purpose of the present study was to determine whether modulation of Na/Si cotransport activity by dietary Si is mediated through regulation of the renal expression of the recently cloned NaSi-1 protein located in the apical brush border membrane (BBM) of the proximal tubule. It was found that rats fed a high Si diet had a marked increase in the renal excretion of Si and a concomitant decrease in BBM Na/Si cotransport activity when compared with rats on a control Si diet. The 43% decrease in BBM Na/Si cotransport activity was associated with a 33% decrease in BBM NaSi-1 protein abundance, as determined by Western blotting, and a 2.7-fold decrease in cortical NaSi-1 mRNA abundance, as determined by Northern blotting. Furthermore, cortical mRNA from rats fed a high Si diet when injected into Xenopus laevis oocytes led to a 2.2-fold decrease in Na/Si cotransport activity compared with mRNA isolated from control Si diet rats. This study indicates that adaptation to a high Si diet is accompanied by a decrease in renal cortical NaSi-1 mRNA abundance, which results in reduced expression of the NaSi-1 protein at the level of the proximal tubular BBM.
Recherche sur Google
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Sulfates
/
ARN messager
/
Protéines de transport
/
Transporteurs de cations
/
Symporteurs
/
Microvillosités
Type d'étude:
Prognostic_studies
Limites:
Animals
Langue:
En
Journal:
J Am Soc Nephrol
Sujet du journal:
NEFROLOGIA
Année:
1998
Type de document:
Article
Pays d'affiliation:
Australie