Natriuretic response to renal medullary endothelin B receptor activation is impaired in Dahl-salt sensitive rats on a high-fat diet.
Physiol Res
; 67(Suppl 1): S149-S154, 2018 06 27.
Article
em En
| MEDLINE
| ID: mdl-29947535
ABSTRACT
Renal medullary endothelin B receptors (ET(B)) mediate sodium excretion and blood pressure (BP) control. Several animal models of hypertension have impaired renal medullary ET(B) function. We found that 4-week high-caloric diet elevated systolic BP in Dahl salt-sensitive (Dahl S) rats (126+/-2 vs. 143+/-3 mm Hg, p<0.05). We hypothesized that renal medullary ET(B) function is dysfunctional in DS rats fed a high-caloric diet. We compared the diuretic and natriuretic response to intramedullary infusion of ET(B) agonist sarafotoxin 6c (S6c) in DS rats fed either a normal or high-caloric diet for 4 weeks. Urine was collected during intramedullary infusion of saline for baseline collection followed by intramedullary infusion of either saline or S6c. We first examined the ET(B) function in DS rats fed a normal diet. S6c increased urine flow (2.7+/-0.3 microl/min during baseline vs. 5.1+/-0.6 microl/min after S6c; p<0.05; n=5) and sodium excretion (0.28+/-0.05 vs. 0.81+/-0.17 micromol/min; p<0.05), suggesting that DS rats have renal medullary ET(B) function. However, DS rats fed a high-caloric diet displayed a significant increase in urine flow (2.7+/-0.4 vs. 4.2+/-0.4 microl/min, baseline vs. S6c infusion, respectively; p<0.05, n=6), but no significant change in sodium excretion in response to S6c (0.32+/-0.06 vs. 0.45+/-0.10 micromol/min). These data demonstrate that renal medullary ET(B) function is impaired in DS rats fed a high-caloric diet, which may be contributed to the elevation of blood pressure during high-caloric feeding in this model.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptor de Endotelina B
/
Ingestão de Alimentos
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Dieta Hiperlipídica
/
Hipertensão
/
Medula Renal
Tipo de estudo:
Diagnostic_studies
/
Etiology_studies
Limite:
Animals
Idioma:
En
Revista:
Physiol Res
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos