Dietary phosphate binding and loading alter kidney angiotensin-converting enzyme mRNA and protein content in 5/6 nephrectomized rats.
Am J Nephrol
; 35(5): 401-8, 2012.
Article
em En
| MEDLINE
| ID: mdl-22517117
ABSTRACT
BACKGROUND:
Vitamin D receptor activation with paricalcitol can modulate the transcription of renin-angiotensin system components in the surgical 5/6 nephrectomy rat model (5/6 NX) of chronic renal insufficiency. We tested the hypothesis whether dietary modification of phosphate influences kidney renin-angiotensin system gene expression at the mRNA level in 5/6 NX rats.METHODS:
Fifteen weeks after surgery, rats were given control diet (0.3% calcium, 0.5% phosphate), phosphate-lowering diet (3% calcium as carbonate) or high-phosphate diet (1.5%) for 12 weeks. Sham-operated rats were on control diet.RESULTS:
Blood pressure, plasma phosphate, parathyroid hormone, glomerulosclerosis, tubulointerstitial damage, and FGF-23 were increased in remnant kidney rats, whereas creatinine clearance was decreased. Phosphate, parathyroid hormone, glomerulosclerosis, tubulointerstitial damage, and FGF-23 were further elevated by the high-phosphate diet, but were reduced by the phosphate-lowering diet. Plasma calcium was increased with the phosphate-lowering diet and decreased with the high-phosphate diet. Remnant kidney rats on control diet showed upregulated kidney angiotensin-converting enzyme (ACE) and angiotensin (Ang) IV receptor (AT(4)) transcription, while ACE2, Ang II type 2 receptor and renin receptor transcription were downregulated in comparison with sham rats. Phosphate-lowering diet reduced whereas high-phosphate diet increased kidney ACE, and these effects were observed at both mRNA and protein levels. Dietary phosphate loading also resulted in lower AT(1a) gene transcription.CONCLUSION:
Dietary phosphate loading was associated with elevated kidney ACE expression, increased tissue damage and lower AT(1a) transcription in 5/6 NX rats. Phosphate binding with 3% calcium carbonate had opposite effects on ACE and kidney damage.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfatos
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Sistema Renina-Angiotensina
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RNA Mensageiro
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Peptidil Dipeptidase A
/
Rim
Limite:
Animals
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article