Mathematical models of action potentials in the periphery and center of the rabbit sinoatrial node (original) (raw)

Mathematical models of the action potential in the periphery and center of the rabbit sinoatrial (SA) node have been developed on the basis of published experimental data. Simulated action potentials are consistent with those recorded experimentally: the model-generated peripheral action potential has a more negative takeoff potential, faster upstroke, more positive peak value, prominent phase 1 repolarization, greater amplitude, shorter duration, and more negative maximum diastolic potential than the model-generated central action potential. In addition, the model peripheral cell shows faster pacemaking. The models behave qualitatively the same as tissue from the periphery and center of the SA node in response to block of tetrodotoxin-sensitive Na+current, L- and T-type Ca2+ currents, 4-aminopyridine-sensitive transient outward current, rapid and slow delayed rectifying K+ currents, and hyperpolarization-activated current. A one-dimensional model of a string of SA node tissue, inco...