The functional role of cardiac T-tubules in a model of rat ventricular myocytes
| Authors | |
|---|---|
| Year of publication | 2006 |
| Type | Article in Periodical |
| Magazine / Source | Philosophical Transactions of the Royal Society |
| MU Faculty or unit | |
| Citation | |
| Field | Biophysics |
| Keywords | accumulation-depletion of ions; transverse tubule; heart; mathematical model; cardiomyocyte; rat |
| Description | The morphology of the cardiac transverse axial tubular system (TATS) has been known for decades, but its function has received little attention. To explore the possible role of this system in the physiological modulation of electrical and contractile activity, we have developed a mathematical model of rat ventricular cardiomyocytes in which the TATS is described as a single compartment. In the model, the action potentials initiated in current clamp mode were accompanied by transient K+ accumulation and transient Ca2+ depletion in the TATS lumen. The amplitude of these changes relative to external ion concentrations was studied at steady state stimulation frequencies of 1 to 5 Hz. Ca2+ depletion increased from 7 % to 13.1 % with stimulation frequency, while K+ accumulation decreased from 4.1 % to 2.7 %. These ionic changes (particularly Ca2+ depletion) implicated significant decrease of intracellular Ca2+ load at frequencies natural for rat heart. |
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