Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Jul;454(4):545-9.
doi: 10.1007/s00424-007-0237-z. Epub 2007 Mar 8.

Transmural variations in gene expression of stretch-modulated proteins in the rat left ventricle

R Stones  1 , S C Calaghan, R Billeter, S M Harrison, E White
Affiliations

Transmural variations in gene expression of stretch-modulated proteins in the rat left ventricle

R Stones et al. Pflugers Arch. 2007 Jul.

Abstract

The properties of left ventricular cardiac myocytes vary transmurally. This may be related to the gradients of stress and strain experienced in vivo across the ventricular wall. We tested the hypothesis that within the rat left ventricle there are transmural differences in the expression of genes for proteins that are involved in mechanosensitive pathways and in associated physiological responses. Real time reverse transcription polymerase chain reaction was used to measure messenger RNA (mRNA) levels of selected targets in sub-epicardial (EPI) and sub-endocardial (ENDO) myocardium. Carbon fibres were attached to single myocytes to stretch them and to record contractility. We observed that the slow positive inotropic response to stretch was not different between EPI and ENDO myocytes and consistent with this, that the mRNA expression of two proteins implicated in the slow response, non-specific cationic mechanosensitive channels (TRPC-1) and Na/H exchanger, were not different. However, mRNA levels of other targets, e.g. the mechanosensitive K(+) channel TREK-1, Brain Natriuretic Peptide and Endothelin-1 receptor B, were significantly greater in ENDO than EPI. No targets had significantly greater mRNA levels in EPI than ENDO. On the basis of these findings, we suggest that the response of the ventricle to stretch will depend upon both the regional differences in stimuli and the relative expression of the mechanosensitive targets and that generally, stretch sensitivity is predicted to be greater in ENDO.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
The inotropic response of left ventricular myocytes to axial stretch. a Representative trace showing the typical biphasic inotropic response of a myocyte to a stretch of 8% from a resting sacromere length (SL) of 1.85 μm. The trace shows changes in active force, resting force has been subtracted with a sample and hold device. The rapid increase in force is seen immediately upon an increase in SL, the slow response develops over the following minutes. b Mean data showing the rapid and slow response to stretch of ≅8% from a resting SL of ≅1.82 μm in sub-epicardial (EPI) and sub-endocardial (ENDO) left ventricular myocytes. The responses from EPI and ENDO cells were not significantly different from each other. P > 0.05, n = 18 EPI , n = 11 ENDO
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'DOI', 'value': '10.1196/annals.1341.028', 'is_inner': False, 'url': 'https://doi.org/10.1196/annals.1341.028'}, {'type': 'PMC', 'value': 'PMC1474840', 'is_inner': False, 'url': 'https://pmc.ncbi.nlm.nih.gov/articles/PMC1474840/'}, {'type': 'PubMed', 'value': '16093507', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/16093507/'}]}
    2. Antzelevitch C (2005) Modulation of transmural repolarization. Ann N Y Acad Sci 1047:314–323 - PMC - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'DOI', 'value': '10.1113/jphysiol.2004.069021', 'is_inner': False, 'url': 'https://doi.org/10.1113/jphysiol.2004.069021'}, {'type': 'PMC', 'value': 'PMC1665066', 'is_inner': False, 'url': 'https://pmc.ncbi.nlm.nih.gov/articles/PMC1665066/'}, {'type': 'PubMed', 'value': '15235080', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/15235080/'}]}
    2. Calaghan S, White E (2004) Activation of Na+–H+ exchange and stretch-activated channels underlies the slow inotropic response to stretch in myocytes and muscle from the rat heart. J Physiol 559:205–214 - PMC - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'DOI', 'value': '10.1016/j.cardiores.2006.06.020', 'is_inner': False, 'url': 'https://doi.org/10.1016/j.cardiores.2006.06.020'}, {'type': 'PubMed', 'value': '16860293', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/16860293/'}]}
    2. Cazorla O, Ait MY, Goret L, Vassort G, Dauzat M, Lacampagne A, Tanguy S, Obert P (2006) Effects of high-altitude exercise training on contractile function of rat skinned cardiomyocyte. Cardiovasc Res 71:652–660 - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'DOI', 'value': '10.1016/j.regpep.2004.12.011', 'is_inner': False, 'url': 'https://doi.org/10.1016/j.regpep.2004.12.011'}, {'type': 'PubMed', 'value': '15837530', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/15837530/'}]}
    2. Cingolani HE, Perez NG, Aiello EA, de Hurtado MC (2005) Intracellular signaling following myocardial stretch: an autocrine/paracrine loop. Regul Pept 128:211–220 - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'PubMed', 'value': '6456085', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/6456085/'}]}
    2. Gorza L, Pauletto P, Pessina AC, Sartore S, Schiaffino S (1981) Isomyosin distribution in normal and pressure-overloaded rat ventricular myocardium. An immunohistochemical study. Circ Res 49:1003–1009 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources