Key result
Dopamine does not directly affect L-type Ca2+ currents or action potentials in isolated myocardial cells.
Why the study?
Does dopamine directly affect the electrophysiological properties of isolated myocardial cells?
Does dopamine directly affect the electrophysiological properties of isolated myocardial cells?
Answers are grounded in this paper and cite their sources.
Dopamine does not directly alter the electrophysiological properties of isolated myocardial cells, suggesting its in vivo inotropic and chronotropic effects are mediated indirectly via catecholamine release.
We examined the electrophysiological effects of dopamine on the single myocardial cells isolated from the rat and rabbit heart. Dopamine at a concentration of 1 or 10 microM did not affect the L-type Ca2+ current (ICa) or the transient outward current (ITO) in rat ventricular, rabbit atrial, ventricular, and sinoatrial node cells. It did not induce any detectable change in the action potential configuration of the rabbit ventricular cells either. We conclude that dopamine does not directly act on myocardial cells at least in terms of the electrophysiological properties.
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Habuchi et al. (1995) studied Normal and hypertrophic myocardium (animal model). Dopamine vs. Baseline/Control was evaluated on L-type Ca2+ current (ICa) and transient outward current (ITO). Dopamine at concentrations of 1 or 10 µM did not directly affect the L-type Ca2+ current, transient outward current, or action potential configuration in isolated rat and rabbit myocardial cells.
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