Linked Life Data

8764245

Source:http://linkedlifedata.com/resource/pubmed/id/8764245

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 2
pubmed:dateCreated
1996-9-19
pubmed:abstractText
Arginine vasopressin (AVP) has been shown to increase the inhibitory influence of the baroreflex on sympathetic nerve activity by a mechanism involving receptors located in the area postrema. The purpose of these experiments was to study the functional effect of this action of AVP by testing the hypothesis that AVP can buffer its own vasoconstrictor effect by facilitating baroreflex-mediated withdrawal of sympathetic nerve activity. Specifically, we determined 1) if AVP can attenuate increases in hindquarter vascular resistance during the infusion of another vasoconstrictor, phenylephrine, and 2) whether the effects of AVP on vascular resistance are associated with appropriate corresponding changes in lumbar sympathetic nerve activity (LSNA). In pentobarbital-anesthetized New Zealand White rabbits the baroreflex was stimulated by phenylephrine-induced elevations in arterial pressure. Baroreflex-mediated changes in heart rate (HR), calculated hindquarter vascular resistance index (R), and LSNA were determined during the simultaneous intravertebral infusion of AVP (0, 0.5, or 1.0 ng.kg-1, min-1). Intravertebral infusion of AVP alone had no effect on resting mean arterial pressure (MAP) but reduced baseline values for LSNA and HR. Intravenous infusion of phenylephrine alone produced dose-dependent increases in MAP and R and decreases in LSNA and HR. The simultaneous infusion of AVP (0.5 or 1.0 ng.kg-1 min-1) and phenylephrine (1.25, 2.5, 5.0, 7.5, and 10.0 micrograms.kg-1.min-1) had no effect on the increase in MAP but attenuated the increases in R and facilitated the reductions in LSNA at all doses of phenylephrine. The higher dose of AVP also enhanced the phenylephrine-induced reductions in HR. In contrast, the intravenous infusion of AVP (1.0 ng.kg-1.min-1) did not alter baroreflex-mediated changes in R, LSNA, or HR. Therefore, we conclude that the action of AVP to increase baroreflex-mediated sympathoinhibition results in an attenuated rise in hindquarter vascular resistance during the infusion of another vasoconstrictor, phenylephrine.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1963-71
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Effect of vasopressin on baroreflex control of lumbar sympathetic nerve activity and hindquarter resistance.
pubmed:affiliation
Department of Pharmacology, University of Texas Health Science Center, San Antonio 78284, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.