Publications by authors named "Lioudmila Polontchouk"

Gap junction channels provide the basis for the electrical syncytial properties of the heart as a communicating electrical network. Cardiac gap junction channels are predominantly composed of connexin 40 or connexin 43. The conductance of these channels (g(j)) can be regulated pharmacologically: substances which activate protein kinase C, protein kinase A or protein kinase G may alter Cx43 gap junction conductance.

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Antiarrhythmic peptides enhance gap junction current in pairs of cardiomyocytes and coupling in cardiac tissue. To elucidate the underlying mechanisms, we investigated the effects of the antiarrhythmic peptide AAP10 (GAG-4Hyp-PY-CONH2) on pairs of adult guinea pig ventricular cardiomyocytes and pairs of HeLa cells transfected with rat cardiac connexin 43 (Cx43). By using a double-cell voltage-clamp technique in pairs of cardiomyocytes, we found that under control conditions the gap junction conductance (gj) steadily decreased with time (by -0.

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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.

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