Interpretation of relevance of sodium-calcium exchange in action potential of diabetic rat heart by mathematical model

Yaras N., TURAN B.

Molecular and Cellular Biochemistry, cilt.269, sa.1, ss.121-129, 2005 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 269 Sayı: 1
  • Basım Tarihi: 2005
  • Doi Numarası: 10.1007/s11010-005-3439-8
  • Dergi Adı: Molecular and Cellular Biochemistry
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.121-129
  • Anahtar Kelimeler: sodium selenite, action potential, calcium current, potassium current, sodium-calcium exchanger, diabetes, NA-CA-EXCHANGE, VENTRICULAR MYOCYTES, INTRACELLULAR CA2+, POTASSIUM CURRENTS, K+ CURRENTS, SELENIUM, INSULIN, CA-2+, CARDIOMYOPATHY, CONTRACTILITY
  • Lokman Hekim Üniversitesi Adresli: Hayır

Özet

Sarcolemmal Na+-Ca2+ exchange plays a central role in ion transport of the myocardium and the current carried with it contributes to the late phase of the action potential (AP) besides the contribution of outward K+-currents. In this study, the mathematical model for AP of the diabetic rat ventricular myocytes [34] was modified and used for the diabetic rat papillary muscle. We used our experimentally measured values of two K+-currents; transient outward current, Ito and steady-state outward current, Iss, as well as L-type Ca2+-current, ICaL, then compared with the simulated values. We have demonstrated that the prolongation in the AP of the papillary muscle of the diabetic rats are not due to the alteration of ICaL but mainly due to the inhibition of the K+-currents and also the Na+-Ca2+ exchanger current, INa-Ca. In combination with our experimental data on sodium-selenite-treated diabetic rats, our simulation results provide new information concerning plausible ionic mechanisms, and second a possible positive effect of selenium treatment on the altered INa-Ca for the observed changes in the AP duration of streptozotocin-induced diabetic rat heart. © Springer Science + Business Media, Inc. 2005.