Characteristic time courses of cortical and medullary sodium signals measured by noninvasive (23) Na-MRI in rat kidney induced by furosemide.
J Magn Reson Imaging
; 41(6): 1622-8, 2015 Jun.
Article
em En
| MEDLINE
| ID: mdl-25168165
ABSTRACT
BACKGROUND:
To characterize regional kidney sodium response by MRI following NKCC2 inhibition.METHODS:
Regional renal sodium signals were monitored noninvasively using (23) Na-MRI at 9.4T with a temporal resolution of 1.5 min in anesthetized rats (N = 14). A mild NKCC2 inhibition was induced using a slow intravenous furosemide infusion. Time course of sodium signal was modeled as an exponential transient with a single characteristic time constant.RESULTS:
Under normal physiological conditions, the renal sodium signals in medullary and cortical regions were stable and found to respond differently to furosemide challenge. Furosemide infusion at 1.2 mg/kg/h (N = 7) increased sodium signal in the cortex by 40 ± 6% (P < 7 × 10(-5) ) whereas decreased in the medulla by 29 ± 2% (P < 3 × 10(-6) ) with different temporal kinetics. The characteristic time constants of the change were determined to be 8 ± 2 and 70 ± 10 min for medulla and cortex. Also, the medullary change occurred 9(±3) times faster than cortical independent of furosemide infusion rate up to 35 mg/kg/h.CONCLUSION:
The pharmacological effects in terms of regional kidney sodium signal changes induced by NKCC2 inhibition are region-specific and highly predictable. Using noninvasive sodium MRI, we obtained regional renal sodium kinetics data sets in response to a low dose furosemide infusion in normal rats.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sódio
/
Imageamento por Ressonância Magnética
/
Diuréticos
/
Furosemida
/
Córtex Renal
/
Medula Renal
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
J Magn Reson Imaging
Assunto da revista:
DIAGNOSTICO POR IMAGEM
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Estados Unidos