Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 2
pubmed:dateCreated
1990-6-13
pubmed:abstractText
In normal heart, presynaptic cholinergic muscarinic and alpha 2-adrenergic mechanisms contribute to regional variations in the rate constant of norepinephrine turnover (kNE), an index of sympathetic neural function. To evaluate these mechanisms in the hypertrophied heart, pulmonary artery-constricted and sham-operated guinea pigs were pretreated with 1) saline vehicle (control) or 2) a combination of quinuclidinyl benzilate (Q), a muscarinic cholinergic antagonist, and yohimbine (Y), an alpha 2-adrenergic antagonist. An increase in kNE was determined in multiple regions of heart from incorporation of radiolabeled tyrosine into norepinephrine during a control period at 24 degrees C and again at 4 degrees C. In sham animals, kNE during cold stress was increased significantly (P less than 0.05) by Q + Y compared with vehicle, confirming that muscarinic cholinergic and/or alpha 2-adrenergic receptors exert a negative-feedback influence on sympathetic neurotransmitter synthesis. In pulmonary artery-constricted animals, in contrast, there were smaller increases in cardiac kNE compared with sham guinea pigs given Q + Y and subjected to cold stress. These data support the concept that muscarinic cholinergic and/or alpha 2-adrenergic presynaptic regulation of cardiac sympathetic function is altered in the hearts and vasculature of pulmonary artery-constricted guinea pigs.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H1375-81
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Ventricular hypertrophy and presynaptic regulation of sympathetic function.
pubmed:affiliation
Veterans Affairs Medical Center, Cardiovascular Center, Iowa City, Iowa.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't