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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4 Pt 2
pubmed:dateCreated
1998-6-2
pubmed:abstractText
Both brain ouabain-like activity ("ouabain") and brain angiotensin II (ANG II) contribute to the sympathoexcitatory and pressor responses to high sodium intake in spontaneously hypertensive (SHR) and Dahl salt-sensitive (Dahl S) rats. To assess whether increases in cerebrospinal fluid (CSF) sodium can mimic this pattern of changes, Wistar rats were chronically infused with artificial CSF (aCSF) or sodium-rich aCSF (0.8 or 1.2 M sodium) intracerebroventricularly through osmotic minipumps for 14 days. Sodium-rich aCSF (0.8 M) was also infused intracerebroventricularly for 2 wk concomitantly with either antibody Fab fragments that bind ouabain and related steroids with high affinity, gamma-globulins as control (200 micrograms/day for both), or the AT1 blocker losartan (1 mg.kg-1.day-1). Sodium-rich aCSF increased CSF sodium from 146 +/- 2 to 152 +/- 2 (0.8 M) and 160 +/- 3 (1.2 M) mmol/l, and increased brain "ouabain" in the hypothalamus, pituitary, and pons. In conscious rats, sodium-rich aCSF increased baseline mean arterial pressure (MAP), enhanced MAP, heart rate (HR), and renal sympathetic nerve activity (RSNA) responses to intracerebroventricular alpha 2-adrenoceptor agonist guanabenz and air stress, and desensitized arterial and cardiopulmonary baroreflex control of HR and RSNA. These effects were largely prevented by intracerebroventricular Fab fragments or losartan. Thus, in Wistar rats, both brain "ouabain" and the brain renin-angiotensin system contribute to sympathoexcitation, impairment of baroreflexes, and hypertension caused by chronically increased CSF sodium. The similar patterns of changes caused by CSF sodium in Wistar rats and by high sodium intake in SHR and Dahl S rats indicate that if high sodium intake increases central sodium, such changes may contribute to sympathoexcitation and hypertension.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1269-76
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Brain "ouabain," ANG II, and sympathoexcitation by chronic central sodium loading in rats.
pubmed:affiliation
University of Ottawa Heart Institute, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't