Interaction of NaCl and behavioral stress on endogenous sodium pump ligands in rats.
Our study investigated the hypothesis that the combination of a high NaCl diet and social isolation stress would increase systolic blood pressure (SBP) and endogenous sodium pump ligands (SPL), ouabainlike compound (OLC), and marinobufagenin (MBG). Excretion of MBG and OLC, SBP, and organ weights were studied in four groups (n = 8) of male Fisher 344 x Norwegian brown rats: controls, socially isolated (Iso), 4% NaCl diet (Salt), and the combination of Salt and Iso (Iso+Salt). In Salt, MBG excretion increased by 78% (P < 0.01), whereas SBP and OLC remained unchanged. In Iso, SBP and MBG did not change, but OLC peaked on day 1. In the Iso+Salt, SBP increased by 9 mmHg, MBG excretion increased (42.0 +/- 7.6 vs. 10.0 +/- 1.5 pmol/24 h, P < 0.01), whereas OLC peaked at day 1 (25.0 +/- 2.5 vs. 10.0 +/- 2.0 pmol/24 h, P < 0.01) and remained elevated. Heart and kidney weights were increased in Salt and Iso+Salt. Aortic weights were increased in Iso and Iso+Salt. Thus a high NaCl intake stimulates MBG excretion, whereas isolation stress stimulates OLC. The combination of Salt and Iso is accompanied by marked stimulation of both SPL.
Fedorova
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OV
Laboratory of Cardiovascular Science, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA. FedorovO@grc.nia.nih.giv
Anderson
D E
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Lakatta
E G
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Bagrov
A Y
AY
D000818:Animals; D002018:Bufanolides / Q000652:urine*; D002298:Cardenolides; D004077:Digoxin; D004326:Drinking / Q000502:physiology; D004435:Eating / Q000502:physiology; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009318:Natriuresis / Q000502:physiology; D009929:Organ Size; D051381:Rats; D011914:Rats, Inbred BN; D011916:Rats, Inbred F344; D012503:Saponins / Q000652:urine*; D012934:Social Isolation; D017673:Sodium Chloride, Dietary / Q000493:pharmacokinetics*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013315:Stress, Psychological / Q000378:metabolism*; D014556:Urine
D002018:Bufanolides; D002298:Cardenolides; D012503:Saponins; D017673:Sodium Chloride, Dietary; C034504:digoxin-like factors; C093896:marinobufagenin; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase