| Electrophysiology and anatomy of embryonic rabbit hearts before and after septation. | |
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MedLine Citation:
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PMID: 15331361 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Mechanisms of cardiac pacemaking and conduction system (CPCS) development are difficult to study, in part because of the absence of models that are physiologically similar to humans in which we can label the entire CPCS. Investigations of the adult rabbit heart have provided insight into normal and abnormal cardiac conduction. The adult and the embryonic rabbit have an endogenous marker of the entire cardiac conduction system, neurofilament 160 (NF-160). Previous work suggested that ventricular septation correlates with critical phases in avian CPCS development, in contrast to the mouse CPCS. Combining high-resolution optical mapping with immunohistochemical analysis of the embryonic rabbit heart, we investigated the significance of ventricular septation in patterning the rabbit embryonic conduction system. We hypothesized that 1) completion of ventricular septation does not correlate with changes in the ventricular activation sequence in rabbit embryos and 2) CPCS anatomy determines the activation sequence of the embryonic heart. We found that preseptated (days 11-13, n = 13) and postseptated (day 15, n = 5) hearts had similar "apex-to-base" ventricular excitation. PR intervals were not significantly different in either group. CPCS anatomy revealed continuity of the NF-160-positive tract connecting the presumptive sinoatrial node, atrioventricular (AV) junction, and ventricular conduction system. The presence of collagen in the AV junction coincided with the appearance of an AV interval. We conclude that the apex-to-base ventricular activation sequence in the rabbit embryo is present before completion of ventricular septation. CPCS anatomy reflects global cardiac activation as demonstrated by high-resolution optical mapping. |
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Authors:
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F Rothenberg; V P Nikolski; M Watanabe; I R Efimov |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. Date: 2004-08-26 |
Journal Detail:
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Title: American journal of physiology. Heart and circulatory physiology Volume: 288 ISSN: 0363-6135 ISO Abbreviation: Am. J. Physiol. Heart Circ. Physiol. Publication Date: 2005 Jan |
Date Detail:
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Created Date: 2004-12-15 Completed Date: 2005-03-22 Revised Date: 2007-11-14 |
Medline Journal Info:
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Nlm Unique ID: 100901228 Medline TA: Am J Physiol Heart Circ Physiol Country: United States |
Other Details:
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Languages: eng Pagination: H344-51 Citation Subset: IM |
Affiliation:
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Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA. fgr@duke.edu |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Biological Clocks / physiology Collagen Type II / metabolism Connexin 43 / metabolism Electrophysiology Embryonic Development Fetal Heart / anatomy & histology*, cytology, metabolism, physiology* Fibroblasts / metabolism Gestational Age Heart Conduction System / embryology Heart Septum / embryology* Heart Ventricles / embryology Myocytes, Cardiac / metabolism Neurofilament Proteins / metabolism Rabbits Tissue Distribution |
| Grant Support | |
ID/Acronym/Agency:
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5T32-HL-07653/HL/NHLBI NIH HHS; HL-58808/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Collagen Type II; 0/Connexin 43; 0/Neurofilament Proteins |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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