Abstract
The unidirectional fluxes of Na+ and Cl- were measured across the isolated gastric mucosa of the bullfrog (R. catesbiana). The addition of strophanthidin, a cardiac aglycone, resulted in marked reductions of the spontaneous potential and short-circuit current. Associated with these changes, the isolated gastric mucosa ceased secreting chloride and hydrogen ion. Although the active component of chloride transfer was inhibited, the exchange diffusion component seemed to increase. No significant changes in membrane conductance or sodium flux were noted. Possible mechanisms of strophanthidin inhibition were discussed in view of its effect on chloride transport across the gastric mucosa and on sodium and potassium transfer in other tissues. It was concluded that the cardiac glycosides may not be specific inhibitors of sodium and potassium transport. This non-specific inhibition suggests that active chloride transport is affected by strophanthidin directly and/or anion secretion is dependent upon normal functioning of cation transport systems in the tissue.
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Selected References
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- COOPERSTEIN I. L., HOGBEN C. A. Ionic transfer across the isolated frog large intestine. J Gen Physiol. 1959 Jan 20;42(3):461–473. doi: 10.1085/jgp.42.3.461. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DURBIN R. P., HEINZ E. Electromotive chloride transport and gastric acid secretion in the frog. J Gen Physiol. 1958 May 20;41(5):1035–1047. doi: 10.1085/jgp.41.5.1035. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HAJDU S. Mechanism of staircase and contracture in ventricular muscle. Am J Physiol. 1953 Sep;174(3):371–380. doi: 10.1152/ajplegacy.1953.174.3.371. [DOI] [PubMed] [Google Scholar]
- HOGBEN C. A. Active transport of chloride by isolated frog gastric epithelium; origin of the gastric mucosal potential. Am J Physiol. 1955 Mar;180(3):641–649. [PubMed] [Google Scholar]
- USSING H. H., ZERAHN K. Active transport of sodium as the source of electric current in the short-circuited isolated frog skin. Acta Physiol Scand. 1951 Aug 25;23(2-3):110–127. doi: 10.1111/j.1748-1716.1951.tb00800.x. [DOI] [PubMed] [Google Scholar]