Taurine on Sino-Atrial Nodal Cells
Taurine, 2-aminoethanesulfonic acid, is a sulfur amino acid that is widely distributed in the body and is involved in many physiological processes1,2. Although taurine is classified as an α-amino acid, it is not incorporated into proteins or membranes. Taurine is present in high concentration (around 10 mM) within myocardial cells, but is found in relatively low levels in the plasma3. It has been found to exert many electrical and mechanical actions on cardiac muscle cells4–7including a positive inotropic effect8,9 and protective action against cellular calcium overload and cardiomyopathy10. Thus, there are many electropharmacological effects of taurine on cardiac muscle cells, but the underlying mechanisms still remain unclear. In the sino-atrial (SA) node, taurine might be a potent modulator of spontaneous activity. The actions of taurine on cardiac pacemaker currents of the SA node are discussed here.
KeywordsAction Potential Duration Sinoatrial Node Negative Chronotropic Effect Positive Chronotropic Effect Spontaneous Beating
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