alexa TPA increases conductance but decreases permeability in neonatal rat cardiomyocyte gap junction channels.
Ophthalmology

Ophthalmology

Journal of Clinical & Experimental Ophthalmology

Author(s): Kwak BR, van Veen TA, Analbers LJ, Jongsma HJ

Abstract Share this page

Abstract Short-term (10 min) effects of 100 nM 12-O-tetradecanoylphorbol-13-acetate (TPA), the protein kinase C (PKC) activator, on cardiac macroscopic (gj) and single channel (gamma j) gap junctional conductances were studied in pairs of neonatal rat cardiomyocytes. Under dual whole-cell (WC) or perforated patch (PP) voltage-clamp, gj increased by 15.5 +/- 7.2\% (mean +/- SD, n = 9) and by 46.3 +/- 17.0\% (n = 5), respectively. The latter difference is not related to intracellular calcium concentration, because raising the Ca2+ concentration in the electrode solution did not change the TPA-induced increase in gj observed under WC conditions. The inactive phorbol ester, 4 alpha-phorbol 12,13-didecanoate (alpha PDD), did not affect gj. Single cardiac gap junction channel events, resolved in the presence of heptanol, indicated two gamma j sizes of 20 and 40-45 pS. Under control conditions, the larger events were most frequently observed. Whereas alpha PDD did not change this distribution, TPA shifted the gamma j distribution to the lower sizes. Diffusion of Lucifer Yellow (LY) and 6-carboxyfluorescein (6-CF), gap junction permeant tracers, was studied on small clusters of cardiomyocytes. Under control conditions, LY labeled 19.4 +/- 7.2 cells (mean +/- SD, n = 18) and 6-CF labeled 8.4 +/- 2.2 cells (n = 20). Whereas alpha PDD did not change the extent of dye transfer, TPA restricted the diffusion of LY to 2.8 +/- 1.3 cells (n = 11) and of 6-CF to 2.4 +/- 1.4 cells (n = 20). This suggests that permeability and single channel conductance of connexin 43 channels are parallely related. Altogether, these results point to the opposite modulation of electrical and metabolic coupling of cardiac cells evoked by TPA. This article was published in Exp Cell Res and referenced in Journal of Clinical & Experimental Ophthalmology

Relevant Expert PPTs

Relevant Speaker PPTs

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri, Food, Aqua and Veterinary Science Journals

Dr. Krish

[email protected]

1-702-714-7001 Extn: 9040

Clinical and Biochemistry Journals

Datta A

[email protected]

1-702-714-7001Extn: 9037

Business & Management Journals

Ronald

[email protected]

1-702-714-7001Extn: 9042

Chemical Engineering and Chemistry Journals

Gabriel Shaw

[email protected]

1-702-714-7001 Extn: 9040

Earth & Environmental Sciences

Katie Wilson

[email protected]

1-702-714-7001Extn: 9042

Engineering Journals

James Franklin

[email protected]

1-702-714-7001Extn: 9042

General Science and Health care Journals

Andrea Jason

[email protected]

1-702-714-7001Extn: 9043

Genetics and Molecular Biology Journals

Anna Melissa

[email protected]

1-702-714-7001 Extn: 9006

Immunology & Microbiology Journals

David Gorantl

[email protected]

1-702-714-7001Extn: 9014

Informatics Journals

Stephanie Skinner

[email protected]

1-702-714-7001Extn: 9039

Material Sciences Journals

Rachle Green

[email protected]

1-702-714-7001Extn: 9039

Mathematics and Physics Journals

Jim Willison

[email protected]

1-702-714-7001 Extn: 9042

Medical Journals

Nimmi Anna

[email protected]

1-702-714-7001 Extn: 9038

Neuroscience & Psychology Journals

Nathan T

[email protected]

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

John Behannon

[email protected]

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

[email protected]

1-702-714-7001 Extn: 9042

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords