Salt intake and renal hemodynamics in immature and mature Dahl salt-sensitive (DS/JR) and salt-resistant (DR/JR) rats.
To determine if abnormalities in the maturation of renal function in Dahl salt-sensitive rats are associated with the development of hypertension, studies were performed in anesthetized 3 week old salt-sensitive (DS/JR) and salt-resistant (DR/JR) rats whose mothers were maintained on 0.15% (low-salt) during gestation and either 0.15% or 2.0% (high-salt) NaC1 diets after parturition. Mature DS/JR and DR/JR rats were maintained on either 0.15% or 2.0% NaC1 diets after weaning and studied at 8 to 9 weeks of age. High-salt diet raised blood pressure (BP) and reduced glomerular filtration rate (GFR) and renal blood flow (RBF) in mature DS/JR rats, but had no effect on BP, GFR and RBF in mature DR/JR rats. In immature DS/JR and DR/JR animals, high-salt intake resulted in poor growth with reductions in GFR and RBF in the DS/JR group. The response to acute volume expansion, (5% body weight physiologic saline infusion) differed among the groups. Mature rats all vasodilated while immature high-salt DS/JR did not, and immature low-salt DS/JR vasoconstricted. These studies demonstrated that both mature and immature DS/JR rats evidence abnormal responses to acute and chronic salt loading. Early exposure to high-salt intake affects the maturation of renal function in the DS/JR group. An enhanced vascular sensitivity to sodium is present at critical periods of postnatal development in DS/JR rats.
Hua
J L
JL
Department of Physiology and Biophysics, State University of New York, Stony Brook 11794-8111.
Kaskel
F J
FJ
Juno
C J
CJ
Moore
L C
LC
McCaughran
J A
JA
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004198:Disease Susceptibility; D004351:Drug Resistance / Q000502:physiology; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D007668:Kidney / Q000254:growth & development; D008297:Male; D010953:Plasma Volume / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation / Q000187:drug effects*; D012982:Sodium, Dietary / Q000009:adverse effects*; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
D012982:Sodium, Dietary