Expression and regulation of connexins in cultured ventricular myocytes isolated from adult rat hearts

Détails

ID Serval
serval:BIB_E73032A2B66C
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Expression and regulation of connexins in cultured ventricular myocytes isolated from adult rat hearts
Périodique
Pflügers Archiv : European Journal of Physiology
Auteur(s)
Polontchouk  L. O., Valiunas  V., Haefliger  J. A., Eppenberger  H. M., Weingart  R.
ISSN
0031-6768 (Print)
Statut éditorial
Publié
Date de publication
03/2002
Volume
443
Numéro
5-6
Pages
676-689
Résumé
Gap junctions were assayed during re-differentiation of adult rat cardiomyocytes in long-term culture to gain insight into the processes of remodeling. Double immunostaining allowed the localization of connexins Cx40, Cx43, and Cx45 between myocytes and demonstrated co-expression and co-localization in individual cells and gap junction plaques, respectively. Immunoblots showed differential time-dependent changes in connexin expression and phosphorylation. The total amount of connexins and the ratio of phosphorylated/non-phosphorylated isoforms gradually increased during the re-establishment of intercellular communication. Dual voltage-clamp studies showed the involvement of several types of gap junction channels. Multichannel currents yielded diverse spectra of g(j,inst)=f( V(j)) and g(j,ss)=f( V(j)) relationships ( g(j,inst): instantaneous gap junction conductance; g(j,ss): conductance at steady state; V(j): transjunctional voltage), indicative of homotypic and heterotypic channels. Single-channel currents revealed two prominent conductances reflecting gamma(j,main) and gamma(j,residual). The histograms of gamma(j,main) showed four discrete peaks (41-44, 59-61, 70-76, and 100-107 pS) attributable to a combination of Cx45-Cx45, Cx40-Cx45 and Cx43-Cx45 channels (1st peak), Cx43-Cx43 and Cx40-Cx43 channels (2nd peak), Cx43-Cx43 channels (3rd peak) and Cx40-Cx40 and Cx40-Cx43 channels (4th peak). However, the presence of heteromeric channels cannot be excluded. The data are consistent with an up-regulation of Cx45 and Cx43 during re-differentiation.
Mots-clé
Age Factors Animals Blotting, Western Cell Differentiation Cells, Cultured Connexin 43/analysis/biosynthesis/metabolism Connexins/analysis/*biosynthesis/metabolism Fluorescent Antibody Technique Gap Junctions/chemistry/*metabolism Heart Ventricles/cytology Ion Channels/physiology Membrane Potentials/physiology Muscle Fibers/chemistry/cytology/*physiology Myocardium/*cytology Patch-Clamp Techniques Phosphorylation Rats
Pubmed
Web of science
Création de la notice
25/01/2008 14:48
Dernière modification de la notice
20/08/2019 17:10
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