Pflügers Archiv

, Volume 388, Issue 3, pp 217–220 | Cite as

Ionophore A23187 induced reductions in toad urinary bladder epithelial cell oxidative phosphorylation and viability

Implications for A23187 related declines in epithelial active transport
  • H. David Humes
  • Joel M. Weinberg
Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands


The divalent cation ionophore A23187 increased oxygen consumption by isolated epithelial cells from toad urinary bladder, an increase similar to that seen with 2,4-dinitrophenol, a classic uncoupler of mitochondrial oxidative phosphorylation. This respiratory stimulation was not seen in calcium-free incubation media. That this A23187 induced rise in cell oxygen consumption was due to a primary uncoupling action on mitochondrial oxidative phosphorylation rather than secondary to stimulation of cellular transport processes and mediated via increased cellular ADP levels was suggested by the ability of A23187 to release the inhibition of cellular respiration by oligomycin, an inhibitor of the mitochondrial proton ATPase which blocks the stimulation of mitochondrial respiration by ADP. Since active transepithelial ion transport and cellular energy production are closely linked processes, the uncoupling action of A23187 in the presence of extracellular calcium is sufficient to account for an acute decline in active ion transport across epithelia without invoking other calcium-mediated processes. Furthermore, isolated epithelial cells exposed to A23187 for 90 min had greater than 50% loss of viability, as measured by failure of Trypan blue exclusion. The subacute A23187 induced declines in transepithelial transport, therefore, may be secondary to its non-specific effects on cell viability.

Key words

Calcium ionophore A23187 Epithelial transport Toad urinary bladder Oxidative phosphorylation Oxygen consumption Cell viability 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Arruda JAL (1979) Calcium inhibits urinary acidification: Effect of ionophore A23187 on the turtle bladder. Pflügers Arch 381: 107–111Google Scholar
  2. 2.
    Babcock DF, First NL, Lardy HA (1976) Action of ionophore A23187 at the cellular level. J Biol Chem 251: 3881–3886Google Scholar
  3. 3.
    Bricker NS, Klahr S (1966) Effects of dinitrophenol and oligomycin on the coupling between anaerobic metabolism and anaerobic sodium transport by the isolated turtle bladder. J Gen Physiol 49: 483–499Google Scholar
  4. 4.
    Estabrook RW (1967) Mitochondrial respiratory control and the polarographic measurement of ADP: O ratios. Methods Enzymol 10: 41–47Google Scholar
  5. 5.
    Girardi AJ, McMichael H, Jr, Henle W (1956) The use of HeLa cells in suspension for the quantitative study of virus propagation. Virology 2: 532–544Google Scholar
  6. 6.
    Friedmann N, Divakaran P, Kirkland J, Kimura S, Wood J (1979) Effects of the calcium ionophore A23187 on liver metabolism. J Pharmacol Exp Ther 211: 127–132Google Scholar
  7. 7.
    Kagawa Y, Racker R (1966) Partial resolution of the enzymes catalyzing oxidative phosphorylation. Properties of a factor conferring oligomycin sensitivity on mitochondrial adenosine triphosphatase. J Biol Chem 241: 2461–2466Google Scholar
  8. 8.
    Kováč L, Hrušovská E, Šmigáň P (1970) Oxidative phosphorylation in yeast. VII. Inhibition of oxidative phosphorylation and of respiratory enzyme synthesis by oligomycin in intact cells. Biochim Biophys Acta 205: 520–523Google Scholar
  9. 9.
    Lardy HA, Connelly JL, Johnson D (1964) Antibiotics as tools for metabolic studies. II. Inhibition of phosphoryl transfer in mitochondria by oligomycin and aurovertin. Biochemistry 12: 1961–1968Google Scholar
  10. 10.
    Lardy HA, Johnson D, McMurray WC (1958) Antibiotics as tools for metabolic studies. I. A survey of toxic antibiotics in the respiratory, phosphorylative, and glycolytic systems. Arch Biochem Biophys 78: 587–597Google Scholar
  11. 11.
    Lehninger AL, Raynafarje B, Vercesi A, Tew WP (1978) Transport and accumulation of calcium in mitochondria. Ann NY Acad Sci 307: 160–176Google Scholar
  12. 12.
    Mitchell P (1979) Keilin's respiratory chain concept and its chemiosmotic consequences. Science 206: 1148–1159Google Scholar
  13. 13.
    Reed PW, Lardy HA (1972) A23187: a divalent cation ionophore. J Biol Chem 247: 6970–6977Google Scholar
  14. 14.
    Schanne FAX, Kane AB, Young EE, Farber JL (1979) Calcium dependence of toxic cell death: a final common pathway. Science 206: 700–702Google Scholar
  15. 15.
    Selwyn MJ, Dawson AP, Dunnett SJ (1970) Calcium transport in mitochondria. FEBS Lett 10: 1–5Google Scholar
  16. 16.
    Tamarit-Rodriguez E, Hellman B, Sehlin J (1977) Metabolic characteristics of pancreatic β-cells exposed to calciumtransporting ionophore. Biochim Biophys Acta 496: 167–174Google Scholar
  17. 17.
    Taylor A, Windhager EE (1979) Possible role of cytosolic calcium and Na−Ca exchange in regulation of transepithelial sodium transport. Am J Physiol 236: F505-F512Google Scholar
  18. 18.
    Van Rossum GDV (1976) The effects of oligomycin on energy metabolism and cation transport in slices of rat liver. Biochim Biophys Acta 423: 111–121Google Scholar
  19. 19.
    Weiner MW, Maffly RH (1978) The provision of cellular metabolic energy for active ion transport. In: Andreoli TE, Hoffman JF, Fanestil DD (eds) Physiology of membrane disorders. Plenum Publishing Corp., New York, p 287Google Scholar
  20. 20.
    Wiesmann W, Sinha S, Klahr S (1977) Effects of ionophore A23187 on baseline and vasopressin stimulated sodium transport in the toad bladder. J Clin Invest 59: 418–425Google Scholar

Copyright information

© Springer-Verlag 1980

Authors and Affiliations

  • H. David Humes
    • 1
  • Joel M. Weinberg
    • 1
  1. 1.Department of Internal MedicineUniversity of MichiganAnn ArborUSA

Personalised recommendations