Altered calcium handling is an early sign of streptozotocin-induced diabetic cardiomyopathy

  • Authors:
    • László Ligeti
    • Orsolya Szenczi
    • Christina M. Prestia
    • Csaba Szabó
    • Katalin Horváth
    • Zoltán L. Marcsek
    • Ruud G.P.M. Van Stiphout
    • Natal A.W. Van Riel
    • Jorn Op Den Buijs
    • Ger J. Van der Vusse
    • Tamás Ivanics
  • View Affiliations

  • Published online on: June 1, 2006     https://doi.org/10.3892/ijmm.17.6.1035
  • Pages: 1035-1043
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Abstract

The main objective of the present study was to determine alterations of calcium handling in the diabetic rat heart during the transition from adaptive to maladaptive phase of cardiomyopathy. By inhibiting the nuclear enzyme poly(ADP-ribose) polymerase (PARP), we also investigated the possible role of this enzyme in the sequence of pathological events. Six weeks after induction of type I diabetes by injection of streptozotocin in rats, the hearts were perfused according to Langendorff. Intracellular-free calcium (Ca2+i) levels were measured by surface fluorometry using Indo-1 AM. Cyclic changes in Ca2+i concentrations and hemodynamic parameters were measured simultaneously. The hearts were challenged by infusion of isoproterenol. Six weeks of diabetes resulted in reduced inotropy and lusitropy. The diabetic hearts (DM) expressed a significantly elevated end-diastolic Ca2+i level (control, 111±20 vs DM, 221±35 nM). The maximal transport capacity of SERCA2a and conductance of RyR2 were reduced. These changes were not accompanied by major alterations in the tissue content of SERCA2a, RyR2, phospholamban and Na+/Ca2+ exchanger. In response to β-adrenergic activation, SERCA2a transport capacity and RyR2 conductance were stunted in the DM hearts. Inhibition of PARP induced minor changes in the mechanical function and calcium handling of the DM hearts. In conclusion, the observed changes in contractility and in Ca2+i handling are most likely attributable to functional disturbances of SERCA2a and RyR2 in this transitional phase of diabetes. At this stage of diabetes, PARP does not appear to play a significant pathogenetic role in the alterations in contractile function and calcium handling.

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June 2006
Volume 17 Issue 6

Print ISSN: 1107-3756
Online ISSN:1791-244X

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Spandidos Publications style
Ligeti L, Szenczi O, Prestia CM, Szabó C, Horváth K, Marcsek ZL, Van Stiphout RG, Van Riel NA, Den Buijs JO, Van der Vusse GJ, Van der Vusse GJ, et al: Altered calcium handling is an early sign of streptozotocin-induced diabetic cardiomyopathy. Int J Mol Med 17: 1035-1043, 2006
APA
Ligeti, L., Szenczi, O., Prestia, C.M., Szabó, C., Horváth, K., Marcsek, Z.L. ... Ivanics, T. (2006). Altered calcium handling is an early sign of streptozotocin-induced diabetic cardiomyopathy. International Journal of Molecular Medicine, 17, 1035-1043. https://doi.org/10.3892/ijmm.17.6.1035
MLA
Ligeti, L., Szenczi, O., Prestia, C. M., Szabó, C., Horváth, K., Marcsek, Z. L., Van Stiphout, R. G., Van Riel, N. A., Den Buijs, J. O., Van der Vusse, G. J., Ivanics, T."Altered calcium handling is an early sign of streptozotocin-induced diabetic cardiomyopathy". International Journal of Molecular Medicine 17.6 (2006): 1035-1043.
Chicago
Ligeti, L., Szenczi, O., Prestia, C. M., Szabó, C., Horváth, K., Marcsek, Z. L., Van Stiphout, R. G., Van Riel, N. A., Den Buijs, J. O., Van der Vusse, G. J., Ivanics, T."Altered calcium handling is an early sign of streptozotocin-induced diabetic cardiomyopathy". International Journal of Molecular Medicine 17, no. 6 (2006): 1035-1043. https://doi.org/10.3892/ijmm.17.6.1035