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.
KeywordsIschemia Cytosol Taurine Washout EGTA
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- 1.Huxtable, RJ., and Sebring, LA, 1983, Cardiovascular actions of taurine. hi Sulfur Amino Acids:Biochemical and Clinical spects(K. Kuriyama, RJ. Iwata and A.R. Liss, eds.), Clin. Aspec., New York, pp. 5–37.Google Scholar
- 3.Huxtable, R.I., and Sebring, L.A., 1980, Cardiovascular actions of taurine. InSulfur Amino Acids: Biochemical and Clinical Aspects(K. Kuriyama, RJ. Huxtable, and H. Iwata, eds.), Alan R Liss, New York, pp. 5–37.Google Scholar
- 5.Schaffer, S.W., Kramer, J., and Chovan, J.P., 1980, Regulation of calcium homeostasis in the heart by taurine.Fed Froc.39: 2691–2694.Google Scholar
- 11.Guo, J., and Noma, A., 1995, A sustained inward current activated at the diastolic potential range inrabbitsino-atrial node cells.J. Physiol. (fond)483: 1–13.Google Scholar
- 12.Noble, D., 1984, The surprising heart: a review of recent progress in cardiac electrophysiology.J. Physiol (Lon d)353: 1–50.Google Scholar
- 18.Lombardini, J.B., 1980, Effect of ischemia on taurine levels. InNatural Sulfur Compounds(D. Cavallini, GE. Gaull, and V. Zappia, eds.), Plenum Press, New York, pp. 255–306.Google Scholar
- 21.Sperelakis, N., Yamamoto, T., Bkaily, G, Sada, H., Sawamura, A., and Azuma, J., 1989, Taurine effects on action potentials and ionic currents in chick myocardial cells. InTaurine and the Heart(H. Iwata, J.B. Lombardini and T. Sagawa, eds.), Kluwer Academic Publisher, Boston, pp. 1–19.CrossRefGoogle Scholar
- 22.Satoh, H., 1994, Cardioprotective actions of taurine against intracellular and extracellular Ca2+-induced effects. InTaurine in Health and Disease(RJ. Huxtable, and D. Michalk, eds.), Plenum Press, New York, pp. 181–196.Google Scholar
- 24.Dolara, P., Ledda, F., Mugelli, A., Mantelli, L, Zilletti, L, Franconi, F., and Giotti, A.,1978, Effect of taurine on calcium, inotropism, and electrical activity of the heart. In:Taurine and Neurological Disorders(A. Barbeau, RJ. Huxtable, eds.), Raven Press, New York, pp. 151–159.Google Scholar