Effect of Ca2+ Efflux Pathway Distribution and Exogenous Ca2+ Buffers on Intracellular Ca2+ Dynamics in the Rat Ventricular Myocyte: A Simulation Study

0430874 - ÚT 2015 RIV US eng J - Článek v odborném periodiku
Pásek, Michal - Šimurda, J. - Orchard, C.
Effect of Ca2+ Efflux Pathway Distribution and Exogenous Ca2+ Buffers on Intracellular Ca2+ Dynamics in the Rat Ventricular Myocyte: A Simulation Study.
BioMed Research International. Roč. 2014, č. 2014 (2014), s. 920208. ISSN 2314-6133. E-ISSN 2314-6141
Grant ostatní: GA MZd NT14301
Institucionální podpora: RVO:61388998
Klíčová slova: calcium efflux * calcium buffers * cardiac myocyte * computer model
Kód oboru RIV: BO - Biofyzika
Impakt faktor: 1.579, rok: 2014

We have used a previously published computer model of the rat cardiac ventricular myocyte to investigate the effect of changing the distribution of Ca efflux pathways (SERCA, Na/Ca exchange, and sarcolemmal Ca ATPase) between the dyad and bulk cytoplasm and the effect of adding exogenous Ca buffers (BAPTA or EGTA), which are used experimentally to differentially buffer Ca in the dyad and bulk cytoplasm, on cellular Ca cycling. Increasing the dyadic fraction of a particular Ca efflux pathway increases the amount of Ca removed by that pathway, with corresponding changes in Ca efflux from the bulk cytoplasm. The magnitude of these effects varies with the proportion of the total Ca removed from the cytoplasm by that pathway. Differences in the response to EGTA and BAPTA, including changes in Ca-dependent inactivation of the L-type Ca current, resulted from the buffers acting as slow and fast “shuttles,” respectively, removing Ca from the dyadic space. The data suggest that complex changes in dyadic Ca and cellular Ca cycling occur as a result of changes in the location of Ca removal pathways or the presence of exogenous Ca buffers, although changing the distribution of Ca efflux pathways has relatively small effects on the systolic Ca transient.
Trvalý link: http://hdl.handle.net/11104/0241389