PÁSEK, Michal, Jiří ŠIMURDA and Clive ORCHARD. Role of t-tubules in the control of trans-sarcolemmal ion flux and intracellular Ca2+ in a model of the rat cardiac ventricular myocyte. European Biophysics Journal With Biophysics Letters. SPRINGER, 2012, vol. 41, No 6, p. 491-503. ISSN 0175-7571. Available from: https://dx.doi.org/10.1007/s00249-012-0804-x.
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Basic information
Original name Role of t-tubules in the control of trans-sarcolemmal ion flux and intracellular Ca2+ in a model of the rat cardiac ventricular myocyte
Authors PÁSEK, Michal (203 Czech Republic, guarantor, belonging to the institution), Jiří ŠIMURDA (203 Czech Republic, belonging to the institution) and Clive ORCHARD (826 United Kingdom of Great Britain and Northern Ireland).
Edition European Biophysics Journal With Biophysics Letters, SPRINGER, 2012, 0175-7571.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10610 Biophysics
Country of publisher Germany
Confidentiality degree is not subject to a state or trade secret
Impact factor Impact factor: 2.274
RIV identification code RIV/00216224:14110/12:00062449
Organization unit Faculty of Medicine
Doi http://dx.doi.org/10.1007/s00249-012-0804-x
UT WoS 000304445400001
Keywords in English t-tubules; rat; cardiac myocyte; computer model; calcium
Tags International impact, Reviewed
Changed by Changed by: Ing. Mgr. Věra Pospíšilíková, učo 9005. Changed: 23/4/2013 00:01.
Abstract
The t-tubules of mammalian ventricular myocytes are invaginations of the surface membrane that form a complex network within the cell, with restricted diffusion to the bulk extracellular space. The trans-sarcolemmal flux of many ions, including Ca2+, occurs predominantly across the t-tubule membrane and thus into and out of this restricted diffusion space. It appears possible, therefore, that ion concentration changes may occur in the t-tubule lumen, which would alter ion flux across the t-tubule membrane. We have used a computer model of the ventricular myocyte, incorporating a t-tubule compartment and experimentally determined values for diffusion between the t-tubule lumen and bulk extracellular space, and ion fluxes across the t-tubule membrane, to investigate this possibility. The results show that influx and efflux of different ion species across the t-tubule membrane are similar, but not equal. Changes of ion concentration can therefore occur close to the t-tubular membrane, thereby altering trans-sarcolemmal ion flux and thus cell function, although such changes are reduced by diffusion to the bulk extracellular space. Slowing diffusion results in larger changes in luminal ion concentrations. These results provide a deeper understanding of the role of the t-tubules in normal cell function, and a basis for understanding the changes that occur in heart failure as a result of changes in t-tubule structure and ion fluxes.
Abstract (in Czech)
Membrána srdečních komorových buněk obsahuje velké množství invaginací zvaných transverzální (t-) tubuly. Hlavní úlohou t-tubulů je rozvedení vzruchu do nitra buněk a zajištění synchronního stahu všech buněčných kontraktilních jednotek (sarkomer). Nedávno publikované matematické modely srdečních komorových buněk savců ukázaly, že během buněčné aktivity dochází uvnitř t-tubulů k významným změnám iontových koncentrací, které ovlivňují tok iontů přes buněčnou membránu, intracelulární náplň Ca2+ a finálně sílu buněčného stahu. Práce představuje implementaci nových experimentálních poznatků do matematického modelu srdeční komorové buňky potkana a upřesňuje roli t-tubulů v řízení buněčné elektromechanické aktivity.
Links
MSM0021622402, plan (intention)Name: Časná diagnostika a léčba kardiovaskulárních chorob
Investor: Ministry of Education, Youth and Sports of the CR, Early diagnostics and treatment of cardiovascular diseases
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