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Patterns of muscular strain in the embryonic heart wall
Author(s) -
Damon Brooke J.,
Rémond Mathieu C.,
Bigelow Michael R.,
Trusk Thomas C.,
Xie Wenjie,
Perucchio Renato,
Sedmera David,
Denslow Stewart,
Thompson Robert P.
Publication year - 2009
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.21958
Subject(s) - biology , embryonic heart , strain (injury) , embryonic stem cell , anatomy , genetics , gene
The hypothesis that inner layers of contracting muscular tubes undergo greater strain than concentric outer layers was tested by numerical modeling and by confocal microscopy of strain within the wall of the early chick heart. We modeled the looped heart as a thin muscular shell surrounding an inner layer of sponge‐like trabeculae by two methods: calculation within a two‐dimensional three‐variable lumped model and simulated expansion of a three‐dimensional, four‐layer mesh of finite elements. Analysis of both models, and correlative microscopy of chamber dimensions, sarcomere spacing, and membrane leaks, indicate a gradient of strain decreasing across the wall from highest strain along inner layers. Prediction of wall thickening during expansion was confirmed by ultrasonography of beating hearts. Degree of stretch determined by radial position may thus contribute to observed patterns of regional myocardial conditioning and slowed proliferation, as well as to the morphogenesis of ventricular trabeculae and conduction fascicles. Developmental Dynamics 238:1535–1546, 2009. © 2009 Wiley‐Liss, Inc.