Linked Life Data

546629

Source:http://linkedlifedata.com/resource/pubmed/id/546629

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1980-8-28
pubmed:abstractText
Rates of isolated embryonic chick hearts (ECH) and embryonic rat hearts (ERH) of various ages were maintained constant by field stimulation and the characteristics of their inotropic responses to isoproterenol (Iso) were investigated. Exposure to Iso produced concentration, age, species and calcium dependent increases in contractility that were prevented by propranolol (3x10(-6) M). The slopes of the linear portions of the concentration-response curves increased with age (14-20 days) in the ERH, the maximal slope and inotropic effect being observed in the 18-day-old heart, whereas they decreased with age (3-7 days) in the ECH, the minimal slope but maximal inotropic effect being observed in the 5-day-old heart. At 10(-7) M, Iso produced approximately maximal responses at all ages in the ECH but elicited only minimal responses at all ages in the ERH, approximately ten times this concentration being required to produce maximal responses in the ERH. Reducing the calcium concentration of the bathing medium significantly increased the sensitivities of the hearts of both species to the inotropic effects of Iso. Iso-induced positive inotropic responses were also demonstrated in isolated, driven ventricles from 4-day-old ECH. These results indicate that functional, beta-adrenergic, inotropic receptors are present in the embryonic hearts of both species and undergo changes in responsiveness during embryonic development which are species-dependent.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0378-5866
pubmed:author
pubmed:issnType
Print
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
276-85
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Adrenergic inotropic responsiveness of embryonic chick and rat hearts.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.