© 1999 by European Society of Cardiology
Copyright © 1999, European Society of Cardiology
Isometric tension development and its calcium sensitivity in skinned myocyte-sized preparations from different regions of the human heart
aLaboratory for Physiology, Institute for Cardiovascular Research (ICaR-VU), Free University, van der Boechorststraat 7, 1081 BT Amsterdam, Netherlands
bDepartment of Cardiology, Institute for Cardiovascular Research (ICaR-VU), Free University, Amsterdam, Netherlands
cDepartment of Cardiac Surgery, Institute for Cardiovascular Research (ICaR-VU), Free University, Amsterdam, Netherlands
* Corresponding author. Tel.: +31-20-444-8121; fax: +31-20-444-8255. E-mail address: J.van_der_Velden.physiol@med.vu.nl (J. van der Velden)
Objective: In this study we investigated whether differences exist or develop in patients with aortic or mitral valve disease in myofibrillar contractile function and contractile protein composition between subendo- and subepicardial human ventricular tissue. Isometric tension, its calcium sensitivity and contractile protein composition were studied in left ventricular subendo- and subepicardial and in atrial biopsies obtained during open heart surgery from 24 patients with mitral or aortic valve disease. Methods: Isometric tension was measured in mechanically isolated skinned myocyte-sized preparations at different free calcium concentrations at 15°C. Protein composition was analysed by one-dimensional gel electrophoresis. A comparison was made between the results of subendo- and subepicardial ventricular tissue within each New York Heart Association class and within the different hemodynamically overloaded groups. Results: Maximal isometric tension was significantly lower in atrial than in ventricular preparations. The concentration of calcium required for half-maximal activation was significantly higher in atrial than in ventricular preparations. Within the ventricle no differences were found in contractile protein composition, isometric tension and its calcium sensitivity between subendo- and subepicardial tissue when all patients were treated as one group or when patients were subdivided according to severity of heart disease or hemodynamic overload. Conclusions: In this group of patients with ventricular volume or pressure overload no regional differences exist or develop during cardiac disease in left ventricular myofibrillar protein composition and force production. Maximal isometric tension and its calcium sensitivity are smaller in atrial than in ventricular preparations.
KEYWORDS Human heart; Contractility; Cardiac diseases; Ventricle; Atrium
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
N. Hamdani, V. Kooij, S. van Dijk, D. Merkus, W. J. Paulus, C. d. Remedios, D. J. Duncker, G. J.M. Stienen, and J. van der Velden Sarcomeric dysfunction in heart failure Cardiovasc Res, March 1, 2008; 77(4): 649 - 658. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. R. Lamberts, N. Hamdani, T. W. Soekhoe, N. M. Boontje, R. Zaremba, L. A. Walker, P. P. de Tombe, J. van der Velden, and G. J. M. Stienen Frequency-dependent myofilament Ca2+ desensitization in failing rat myocardium J. Physiol., July 15, 2007; 582(2): 695 - 709. [Abstract] [Full Text] [PDF] |
||||
![]() |
J van der Velden, Z Papp, N.M Boontje, R Zaremba, J.W de Jong, P.M.L Janssen, G Hasenfuss, and G.J.M Stienen The effect of myosin light chain 2 dephosphorylation on Ca2+-sensitivity of force is enhanced in failing human hearts Cardiovasc Res, February 1, 2003; 57(2): 505 - 514. [Abstract] [Full Text] [PDF] |
||||
![]() |
J van der Velden, Z Papp, R Zaremba, N.M Boontje, J.W de Jong, V.J Owen, P.B.J Burton, P Goldmann, K Jaquet, and G.J.M Stienen Increased Ca2+-sensitivity of the contractile apparatus in end-stage human heart failure results from altered phosphorylation of contractile proteins Cardiovasc Res, January 1, 2003; 57(1): 37 - 47. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. van der Velden, J.W. de Jong, V.J. Owen, P.B.J. Burton, and G.J.M. Stienen Effect of protein kinase A on calcium sensitivity of force and its sarcomere length dependence in human cardiomyocytes Cardiovasc Res, June 1, 2000; 46(3): 487 - 495. [Abstract] [Full Text] [PDF] |
||||

