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

Autor: Rudolf Billeter, Sarah Calaghan, Simon M. Harrison, Ed White, Rachel Stones
Jazyk: angličtina
Rok vydání: 2007
Předmět:
medicine.medical_specialty
Sodium-Hydrogen Exchangers
Physiology
Heart Ventricles
Clinical Biochemistry
030204 cardiovascular system & hematology
Biology
Cardiovascular System
Mechanotransduction
Cellular
Contractility
Rats
Sprague-Dawley
03 medical and health sciences
Transient receptor potential channel
0302 clinical medicine
Potassium Channels
Tandem Pore Domain
Physiology (medical)
Internal medicine
Gene expression
Natriuretic Peptide
Brain
medicine
Myocyte
Animals
Myocytes
Cardiac
RNA
Messenger
Receptor
030304 developmental biology
TRPC Cation Channels
0303 health sciences
Messenger RNA
Stretch
TRP channels
Receptor
Endothelin B
Cardiac myocytes
Cell biology
Rats
medicine.anatomical_structure
Endocrinology
Gene Expression Regulation
Ventricle
Mechanosensitive channels
Stretch-activated channel
Zdroj: Pflugers Archiv
ISSN: 1432-2013
0031-6768
Popis: 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.
Databáze: OpenAIRE
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