Role of Na+-Ca2+ exchange in neonatal and adult ventricular cells

Hitomi I. Sano, Yasuhiro Naito, Masaru Tomita

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The present paper expanded an integrated mathematical model, which successfully simulated developmental changes in electrophysiological activities of rodent ventricular cells, to contrive models that reflect one of the hypothesis on the role of Na+-Ca"+ exchange in neonatal ventricular cell: the Na+-Ca+ exchange assumes a relatively greater role in neonatal cells with a morphologically sparse SR. Our simulation with the expanded model showed that neonatal ventricular cell consumed larger amount of adenosine triphosphate (ATP) than adult ventricular cell did, owing to long relaxation time. The amount of ATP consumed per beat was reduced to the amount equivalent to adult ventricular cell, as increasing the relative current density of Na+-Ca2+ exchange (F NCx) by 4-fold, which is consistent with the observed current density in neonatal rabbit ventricular cell. To further validate the hypothesis, the relative functional activity of SR (FSR) was incrementally increased from neonatal to adult levels and subsequently increased FNCX, and found that increasing FNcx had negative impact on sarcomere relaxation velocity in ventricular cell model with large FSR. All the results thus theoretically supported the hypothesis that the Na+-Ca2+ exchange assumes a relatively greater role in neonatal cells with a morphologically sparse SR.

Original languageEnglish
Title of host publicationWMSCI 2008 - The 12th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with the 14th International Conference on Information Systems Analysis and Synthesis, ISAS 2008 - Proc.
Pages142-144
Number of pages3
Publication statusPublished - 2008 Dec 1
Event12th World Multi-Conference on Systemics, Cybernetics and Informatics, WMSCI 2008, Jointly with the 14th International Conference on Information Systems Analysis and Synthesis, ISAS 2008 - Orlando, FL, United States
Duration: 2008 Jun 292008 Jul 2

Publication series

NameWMSCI 2008 - The 12th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with the 14th International Conference on Information Systems Analysis and Synthesis, ISAS 2008 - Proc.
Volume2

Other

Other12th World Multi-Conference on Systemics, Cybernetics and Informatics, WMSCI 2008, Jointly with the 14th International Conference on Information Systems Analysis and Synthesis, ISAS 2008
CountryUnited States
CityOrlando, FL
Period08/6/2908/7/2

Keywords

  • Cardiac ventricular cell
  • Development
  • Electrophysiology
  • Excitation- contraction (E-C) coupling
  • Sodium-Calcium exchanger

ASJC Scopus subject areas

  • Artificial Intelligence
  • Computer Networks and Communications

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    Sano, H. I., Naito, Y., & Tomita, M. (2008). Role of Na+-Ca2+ exchange in neonatal and adult ventricular cells. In WMSCI 2008 - The 12th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with the 14th International Conference on Information Systems Analysis and Synthesis, ISAS 2008 - Proc. (pp. 142-144). (WMSCI 2008 - The 12th World Multi-Conference on Systemics, Cybernetics and Informatics, Jointly with the 14th International Conference on Information Systems Analysis and Synthesis, ISAS 2008 - Proc.; Vol. 2).