Linked Life Data

11454557

Source:http://linkedlifedata.com/resource/pubmed/id/11454557

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-7-16
pubmed:abstractText
The relative contributions of a central neural oscillator and of the delay in alpha-adrenergic transmission within the baroreflex loop in the predominance of low-frequency (LF) cardiovascular variability during sympathetic activation in humans are unclear. We measured R-R interval (RR), muscle sympathetic nerve activity (MSNA), blood pressure (BP), and their variability in 10 normal subjects during sympathetic activation achieved by BP lowering with sodium nitroprusside (SNP) and alpha-adrenergic blockade using phentolamine. SNP and phentolamine induced comparable reductions in BP (P > 0.25). Despite tachycardia and sympathetic activation with both SNP and phentolamine, LF variability in RR, MSNA, and BP increased during SNP and decreased during phentolamine (SNP: RR +20 +/- 6%, MSNA +3 +/- 5%, systolic BP +9 +/- 6%, diastolic BP +7 +/- 5%; phentolamine: RR -2 +/- 7%, MSNA -34 +/- 6%, systolic BP -16 +/- 8%, diastolic BP -13 +/- 4%, P < 0.05 except systolic BP, where P = 0.09). Thus LF variability is reduced when sympathetic activation is induced by alpha-adrenergic blockade. This suggests that alpha-adrenergic transmission within the baroreflex loop may contribute importantly to the predominance of LF cardiovascular variability associated with sympathetic excitation in humans.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0363-6135
pubmed:author
pubmed:issnType
Print
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H559-65
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Contrasting effects of phentolamine and nitroprusside on neural and cardiovascular variability.
pubmed:affiliation
Department of Cardiology/Hypertension Clinic, Erasme Hospital, 1070 Brussels, Belgium.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't