Linked Life Data

2865348

Source:http://linkedlifedata.com/resource/pubmed/id/2865348

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1985-12-20
pubmed:abstractText
We used standard microelectrode techniques to study developmental changes in the transmembrane potentials of sinus nodes from 1- to 10-day-old and adult rabbits superfused with Tyrode's solution at 37 degrees C. Maximum diastolic potential did not change with age, but action potential amplitude in day 1 to 3 hearts was lower than that in adults. Sinus cycle length (SCL) also was shorter in the young sinus nodes. In experiments on beta adrenergic stimulation the reduction of SCL in the young occurred at lower isoproterenol concentrations than in the adult, but the maximum reduction in SCL was the same at both ages (-40%). The alpha agonist, phenylephrine, had no age-dependent effect on SCL or action potential characteristics in either age group. In addition, the inhibitory effect of alpha stimulation demonstrated previously in automatic fibers of the ventricular specialized conducting system and atrium did not occur in sinus node. Studies of Purkinje fibers demonstrated this inhibitory effect to be voltage-dependent; it did not occur at membrane potentials in the range of those in the sinus node. Our results suggest that whereas developmental changes in the response to beta adrenergic stimulation are demonstrable in the sinus node, there are no such changes in the response to alpha adrenergic stimulation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
235
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
308-12
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Developmental changes in the rabbit sinus node action potential and its response to adrenergic agonists.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.