Journal article
Characterization of embryonic cardiac pacemaker and atrioventricular conduction physiology in Xenopus laevis using noninvasive imaging
American journal of physiology. Heart and circulatory physiology, Vol.286(6), pp.H2035-H2041
06/2004
DOI: 10.1152/ajpheart.00807.2003
PMCID: PMC3530895
PMID: 15148055
Abstract
Congenital heart defects often include altered conduction as well as morphological changes. Model organisms, like the frog
Xenopus laevis
, offer practical advantages for the study of congenital heart disease.
X. laevis
embryos are easily obtained free living, and the developing heart is readily visualized. Functional and morphological evidence for a conduction system is available for adult frog hearts, but information on the normal properties of embryonic heart contraction is lacking, especially in intact animals. With the use of fine glass microelectrodes, we were able to obtain cardiac recordings and make standard electrophysiological measurements in 1-wk-old embryos (
stage 46
). In addition, a system using digital analysis of video images was adapted for measurement of the standard cardiac intervals and compared with invasive measurements. Video images were obtained of the heart in live, pharmacologically paralyzed,
stage 46 X. laevis
embryos. Normal values for the timing of the cardiac cycle were established. Intervals determined by video analysis (
n
= 53), including the atrial and ventricular cycle lengths (473 ± 10 ms and 464 ± 19 ms, respectively) and the atrioventricular interval (169 ± 5 ms) were not statistically different from those determined by intrathoracic cardiac recordings. We also present the data obtained from embryos treated with standard medications that affect the human conduction system. We conclude that the physiology of embryonic
X. laevis
cardiac conduction can be noninvasively studied by using digital video imaging. Additionally, we show the response of
X. laevis
embryonic hearts to chronotropic agents is similar but not identical to the response of the human heart.
Details
- Title: Subtitle
- Characterization of embryonic cardiac pacemaker and atrioventricular conduction physiology in Xenopus laevis using noninvasive imaging
- Creators
- Heather L Bartlett - Division of Cardiology, Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242Thomas D Scholz - Division of Cardiology, Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242Fred S Lamb - Division of Cardiology, Department of Pediatrics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242Daniel L Weeks - Department of Biochemistry, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Heart and circulatory physiology, Vol.286(6), pp.H2035-H2041
- DOI
- 10.1152/ajpheart.00807.2003
- PMID
- 15148055
- PMCID
- PMC3530895
- NLM abbreviation
- Am J Physiol Heart Circ Physiol
- ISSN
- 0363-6135
- eISSN
- 1522-1539
- Grant note
- P50 HL062178-050003 || HL / National Heart, Lung, and Blood Institute : NHLBI
- Language
- English
- Date published
- 06/2004
- Academic Unit
- Cardiology; Stead Family Department of Pediatrics; Child and Community Health; Biochemistry and Molecular Biology
- Record Identifier
- 9984025290102771
Metrics
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