Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-3-5
pubmed:abstractText
Congenital heart block (CHB) is a conduction abnormality characterized by complete atrioventricular (AV) block. CHB affects fetuses and/or newborn of mothers with autoantibodies reactive with ribonucleoproteins 48-kDa SSB/La, 52-kDa SSA/Ro, and 60-kDa SSA/Ro. We recently established animal models of CHB and reported, for the first time, significant sinus bradycardia preceding AV block. This unexpected observation implies that the spectrum of conduction abnormalities extends beyond the AV node to also affect the SA node. To test this hypothesis, we investigated the functional basis of this sinus bradycardia by characterizing the effects of antibodies from mothers with CHB children (positive IgG) on ionic currents that are known to significantly contribute to spontaneous pacing in SA node cells. We recorded L- (I(Ca.L)) and T- (I(Ca.T)) type Ca2+, delayed rectifier K+ (I(K)), hyperpolarization-activated (I(f)) currents, and action potentials (APs) from young rabbit SA node cells. We demonstrated that positive IgG significantly inhibited both I(Ca.T) and I(Ca.L) and induced sinus bradycardia but did not affect I(f) and I(K). Normal IgG from mothers with healthy children did not affect all the currents studied and APs. These results establish that IgG from mothers with CHB children causes substantial inhibition of I(Ca.T) and I(Ca.L), two important pacemaker currents in rabbit SA node cells and point to both I(Ca.T) and I(Ca.L) as major players in the ionic mechanism by which maternal antibodies induce sinus bradycardia in CHB. These novel findings have important clinical significance and suggest that sinus bradycardia may be a potential marker in the detection and prevention of CHB. The full text of this article is available online at http://circres.ahajournals.org
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antibodies, Antinuclear, http://linkedlifedata.com/resource/pubmed/chemical/Autoantigens, http://linkedlifedata.com/resource/pubmed/chemical/Calcium, http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels, L-Type, http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels, T-Type, http://linkedlifedata.com/resource/pubmed/chemical/Immunoglobulin G, http://linkedlifedata.com/resource/pubmed/chemical/RNA, Small Cytoplasmic, http://linkedlifedata.com/resource/pubmed/chemical/Ribonucleoproteins, http://linkedlifedata.com/resource/pubmed/chemical/SS-A antibodies, http://linkedlifedata.com/resource/pubmed/chemical/SS-A antigen, http://linkedlifedata.com/resource/pubmed/chemical/SS-B antigen, http://linkedlifedata.com/resource/pubmed/chemical/TROVE2 protein, human
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1524-4571
pubmed:author
pubmed:issnType
Electronic
pubmed:day
5
pubmed:volume
94
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
e32-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:14963005-Action Potentials, pubmed-meshheading:14963005-Adult, pubmed-meshheading:14963005-Animals, pubmed-meshheading:14963005-Antibodies, Antinuclear, pubmed-meshheading:14963005-Arrhythmia, Sinus, pubmed-meshheading:14963005-Autoantigens, pubmed-meshheading:14963005-Bradycardia, pubmed-meshheading:14963005-Calcium, pubmed-meshheading:14963005-Calcium Channels, L-Type, pubmed-meshheading:14963005-Calcium Channels, T-Type, pubmed-meshheading:14963005-Female, pubmed-meshheading:14963005-Heart Block, pubmed-meshheading:14963005-Humans, pubmed-meshheading:14963005-Immunity, Maternally-Acquired, pubmed-meshheading:14963005-Immunoglobulin G, pubmed-meshheading:14963005-Ion Transport, pubmed-meshheading:14963005-Pregnancy, pubmed-meshheading:14963005-RNA, Small Cytoplasmic, pubmed-meshheading:14963005-Rabbits, pubmed-meshheading:14963005-Ribonucleoproteins, pubmed-meshheading:14963005-Sinoatrial Node
pubmed:year
2004
pubmed:articleTitle
Functional basis of sinus bradycardia in congenital heart block.
pubmed:affiliation
Molecular and Cellular Cardiology Program, VA New York Harbor Healthcare System, SUNY Downstate Medical Center and NYU School of Medicine, Brooklyn, NY 11209, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.