Concentration changes in Ca2+ and K+ in the t-tubules of rat and guinea pig as estimated in two models of ventricular myocytes
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| Year of publication | 2004 |
| Type | Conference abstract |
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| Description | To explore the possible role of t-tubular system in the physiological modulation of cardiac electrical and contractile activity, we designed mathematical models of guinea pig and rat ventricular cardiomyocytes in which the t-tubules were described as a single compartment. In both models, action potential responses to brief stimulations in current clamp are accompanied by transient K+ accumulation and transient Ca2+ depletion in the t-tubule lumen. The amplitude of these changes, relative to external ion concentrations, was studied at steady state at frequencies of 1 to 5 Hz. In the rat model, Ca2+ depletion increased from 11.8 % to 20.8 % with stimulation frequency. Meanwhile, K+ accumulation decreased from 4.3 % to 3 %. On the contrary, the guinea pig model exhibited decrease of tubular Ca2+ depletion from 15.6 % to 7.1 % and increase of tubular K+ accumulation from 2.5 % to 3.4 % in the same frequency range. |
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