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This Article Full Text Full Text (PDF) All Versions of this Article: 93/3/370    most recent expphysiol.2007.040659v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Banyasz, T. Articles by Balke, C. W. Search for Related Content PubMed PubMed Citation Articles by Banyasz, T. Articles by Balke, C. W.

¹ Department of Physiology, University of Debrecen, Debrecen, Hungary ² Department of Internal Medicine, University of Kentucky, Lexington, KY 40536, USA

We characterized the morphological, electrical and mechanical alterations of cardiomyocytes in long-term cell culture. Morphometric parameters, sarcomere length, T-tubule density, cell capacitance, L-type calcium current (I_Ca,L), inward rectifier potassium current (I_K1), cytosolic calcium transients, action potential and contractile parameters of adult rat ventricular myocytes were determined on each day of 5 days in culture. We also analysed the health of the myocytes using an apoptotic/necrotic viability assay. The data show that myocytes undergo profound morphological and functional changes during culture. We observed a progressive reduction in the cell area (from 2502 ± 70 µm² on day 0 to 1432 ± 50 µm² on day 5), T-tubule density, systolic shortening (from 0.11 ± 0.02 to 0.05 ± 0.01 µm) and amplitude of calcium transients (from 1.54 ± 0.19 to 0.67 ± 0.19) over 5 days of culture. The negative force–frequency relationship, characteristic of rat myocardium, was maintained during the first 2 days but diminished thereafter. Cell capacitance (from 156 ± 8 to 105 ± 11 pF) and membrane currents were also reduced (I_Ca,L, from 3.98 ± 0.39 to 2.12 ± 0.37 pA pF; and I_K1, from 34.34p ± 2.31 to 18.00 ± 5.97 pA pF^–1). We observed progressive depolarization of the resting membrane potential during culture (from 77.3 ± 2.5 to 34.2 ± 5.9 mV) and, consequently, action potential morphology was profoundly altered as well. The results of the viability assays indicate that these alterations could not be attributed to either apoptosis or necrosis but are rather an adaptation to the culture conditions over time.

(Received 11 September 2007; accepted after revision 6 December 2007; first published online 21 December 2007)
Corresponding author T. Banyasz: University of Kentucky, BBSRB-Room B251, 741 South Limestone Street, Lexington, KY 40536-0509, USA. Email: tbany2{at}email.uky.edu