Abstract
A tannin isolated from Paullinia pinnata Linn., and tannic acid, have cardiotonic actions on the isolated perfused frog heart. Paullinia tannin is more firmly “fixed” than tannic acid. Tannin solutions contain peroxide, but the cardiotonic action is not dependent on this, since drugs believed to prevent peroxide formation, and sodium pyruvate which destroys peroxides, do not prevent the cardiotonic action. Maximal stimulation by tannin greatly reduces subsequent stimulation by ouabain. If calcium is omitted from the Ringer solution tannins cannot stimulate the heart. In this respect they differ from ouabain. However, the ouabain stimulation can be prevented by prior perfusion with tannin. It is suggested that the antagonism between tannin and ouabain is due to the former preventing ouabain from reaching its receptor sites, and that tannin stimulation is dependent on the formation of a calcium-tannin complex at the heart surface. In the isolated perfused mammalian heart preparation tannins increase diastolic tonus and coronary flow.
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Selected References
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- EDELBERG R. The action of tannic acid on model systems formed of constituents of the erythrocyte membrane. J Cell Physiol. 1953 Feb;41(1):37–50. doi: 10.1002/jcp.1030410104. [DOI] [PubMed] [Google Scholar]
- EDELBERG R. The action of tannic acid on the erythrocyte membrane. J Cell Physiol. 1952 Dec;40(3):529–548. doi: 10.1002/jcp.1030400312. [DOI] [PubMed] [Google Scholar]
- HAJDU S., LEONARD E. The cellular basis of cardiac glycoside action. Pharmacol Rev. 1959 Jun;11(2 Pt 1):173–209. [PubMed] [Google Scholar]
- LOEWI O. On the mechanism of the positive inotropic action of fluoride, oleate, and calcium on the frog's heart. J Pharmacol Exp Ther. 1955 May;114(1):90–99. [PubMed] [Google Scholar]
- MOULIN M., WILBRANDT W. Die Wirkung von Kalium und Calcium auf das Treppenhänomen am Froschherzen. Experientia. 1955 Feb 15;11(2):72–73. doi: 10.1007/BF02179035. [DOI] [PubMed] [Google Scholar]
- NIEDERGERKE R., HARRIS E. J. Accumulation of calcium (or strontium) under conditions of increasing contractility. Nature. 1957 May 25;179(4569):1068–1069. doi: 10.1038/1791068a0. [DOI] [PubMed] [Google Scholar]
- NIEDERGERKE R., LUTTGAU H. C. Antagonism between calcium and sodium ions. Nature. 1957 May 25;179(4569):1066–1067. doi: 10.1038/1791066a0. [DOI] [PubMed] [Google Scholar]