Trabeculae carneae as models of the ventricular walls: implications for the delivery of oxygen

Show simple item record Goo, SY en Joshi, P en Sands, Gregory en Gerneke, DA en Taberner, Andrew en Dollie, Q en Le Grice, Ian en Loiselle, Denis en 2011-09-06T21:42:43Z en 2009 en
dc.identifier.citation J Gen Physiol 134(4):339-350 Oct 2009 en
dc.identifier.issn 0022-1295 en
dc.identifier.uri en
dc.description.abstract Trabeculae carneae are the smallest naturally arising collections of linearly arranged myocytes in the heart. They are the preparation of choice for studies of function of intact myocardium in vitro. In vivo, trabeculae are unique in receiving oxygen from two independent sources: the coronary circulation and the surrounding ventricular blood. Because oxygen partial pressure (PO2) in the coronary arterioles is identical in specimens from both ventricles, whereas that of ventricular blood is 2.5-fold higher in the left ventricle than in the right ventricle, trabeculae represent a “natural laboratory” in which to examine the influence of “extravascular” PO2 on the extent of capillarization of myocardial tissue. We exploit this advantage to test four hypotheses. (1) In trabeculae from either ventricle, a peripheral annulus of cells is devoid of capillaries. (2) Hence, sufficiently small trabeculae from either ventricle are totally devoid of capillaries. (3) The capillary-to-myocyte ratios in specimens from either ventricle are identical to those of their respective walls. (4) Capillary-to-myocyte ratios are comparable in specimens from either ventricle, reflecting equivalent energy demands in vivo, driven by identical contractile frequencies and comparable wall stresses. We applied confocal fluorescent imaging to trabeculae in cross section, subsequently using semi-automated segmentation techniques to distinguish capillaries from myocytes. We quantified the capillary-to-myocyte ratios of trabeculae from both ventricles and compared them to those determined for the ventricular free walls and septum. Quantitative interpretation was furthered by mathematical modeling, using both the classical solution to the diffusion equation for elliptical cross sections, and a novel approach applicable to cross sections of arbitrary shape containing arbitrary disposition of capillaries and non-respiring collagen cords. en
dc.language EN en
dc.publisher The Rockefeller University Press en
dc.relation.ispartofseries Journal of General Physiology en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. Details obtained from en
dc.rights.uri en
dc.rights.uri en
dc.subject PAPILLARY-MUSCLE en
dc.subject HEAT-PRODUCTION en
dc.subject CAPILLARY BED en
dc.subject METABOLISM en
dc.subject MICROSCOPY en
dc.subject DIFFUSION en
dc.subject HYPERTROPHY en
dc.subject MYOCARDIUM en
dc.subject MYOGLOBIN en
dc.title Trabeculae carneae as models of the ventricular walls: implications for the delivery of oxygen en
dc.type Journal Article en
dc.identifier.doi 10.1085/jgp.200910276 en
pubs.issue 4 en
pubs.begin-page 339 en
pubs.volume 134 en
dc.rights.holder Copyright: the author en
dc.identifier.pmid 19752188 en
pubs.end-page 350 en
dc.rights.accessrights en
pubs.subtype Article en
pubs.elements-id 89832 en Bioengineering Institute en ABI Associates en Medical and Health Sciences en Medical Sciences en Physiology Division en
pubs.record-created-at-source-date 2010-09-01 en
pubs.dimensions-id 19752188 en

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