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. 1980 Sep 1;76(3):381–393. doi: 10.1085/jgp.76.3.381

Control of active proton transport in turtle urinary bladder by cell pH

PMCID: PMC2228600  PMID: 7420049

Abstract

The rate of active H+ secretion (JH) across the luminal cell membrane of the turtle bladder decreases linearly with the chemical (delta pH) or electrical potential gradient (delta psi) against which secretion occurs. To examine the control of JH from the cell side of the pump, acid-base changes were imposed on the cellular compartment by increasing serosal[HCO3-] at constant PCO2 or by varying PCO2 at constant [HCO3-]. When serosal [HCO3-] was increased from 0 to 60 mM, cell [H+] decreased, as estimated by the 5,5-dimethyloxazoladine-2,4- dione method. JH was a saturable function of cell [H+], with an apparent Km of 25 nM. When PCO2 was varied between 1 and 20% at various serosal Km of 25 nM. When PCO2 was varied between 1 and 20% at various serosal [HCO3-], the PCO2 required to reach a maximal JH increased with [HCO3-] so that JH was a function of cell [H+] rather than of cell [HCO3-] or CO2. The proton pump was controlled asymmetrically with respect to the pH component of the electrochemical potential for protons, microH. On the cell side of the pump, a delta pH of < 1 U was required to vary JH between maximal and zero values, whereas on the luminal side a delta pH of 3 U was required. Cell [H+] regulates JH by determining the availability of H+ to the pump in a relationship resembling Michaelis-Menten kinetics. Increasing luminal [H+] generates an energy barrier at a luminal pH near 4.4 that equals the free energy (per H+ translocated) of the metabolic driving reaction.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Al-awqati Q., Mueller A., Steinmetz P. R. Transport of H+ against electrochemical gradients in turtle urinary bladder. Am J Physiol. 1977 Dec;233(6):F502–F508. doi: 10.1152/ajprenal.1977.233.6.F502. [DOI] [PubMed] [Google Scholar]
  2. Alberty R. A. Effect of pH and metal ion concentration on the equilibrium hydrolysis of adenosine triphosphate to adenosine diphosphate. J Biol Chem. 1968 Apr 10;243(7):1337–1343. [PubMed] [Google Scholar]
  3. Beauwens R., Al-Awqati Q. Active H+ transport in the turtle urinary bladder. Coupling of transport to glucose oxidation. J Gen Physiol. 1976 Oct;68(4):421–439. doi: 10.1085/jgp.68.4.421. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bowman B. J., Slayman C. W. Characterization of plasma membrane adenosine triphosphatase of Neurospora crassa. J Biol Chem. 1977 May 25;252(10):3357–3363. [PubMed] [Google Scholar]
  5. Cohen L. H., Mueller A., Steinmetz P. R. Inhibition of the bicarbonate exit step in urinary acidification by a disulfonic stilbene. J Clin Invest. 1978 Apr;61(4):981–986. doi: 10.1172/JCI109023. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dixon T. E., Al-Awqati Q. Urinary acidification in turtle bladder is due to a reversible proton-translocating ATPase. Proc Natl Acad Sci U S A. 1979 Jul;76(7):3135–3138. doi: 10.1073/pnas.76.7.3135. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hirschhorn N., Frazier H. S. Intracellular electrical potential of the epithelium of turtle bladder. Am J Physiol. 1971 May;220(5):1158–1161. doi: 10.1152/ajplegacy.1971.220.5.1158. [DOI] [PubMed] [Google Scholar]
  8. Kaback H. R. Molecular biology and energetics of membrane transport. J Cell Physiol. 1976 Dec;89(4):575–593. doi: 10.1002/jcp.1040890414. [DOI] [PubMed] [Google Scholar]
  9. Malnic G., De Mello Aires M., Giebisch G. Micropuncture study of renal tubular hydrogen ion transport in the rat. Am J Physiol. 1972 Jan;222(1):147–158. doi: 10.1152/ajplegacy.1972.222.1.147. [DOI] [PubMed] [Google Scholar]
  10. Mello Aires M., Malnic G. Peritubular pH and PCO'2 in renal tubular acidification. Am J Physiol. 1975 Jun;228(6):1766–1774. doi: 10.1152/ajplegacy.1975.228.6.1766. [DOI] [PubMed] [Google Scholar]
  11. Schilb T. P., Brodsky W. A. CO 2 gradients and acidification by transport of HCO 3 in turtle bladders. Am J Physiol. 1972 Feb;222(2):272–281. doi: 10.1152/ajplegacy.1972.222.2.272. [DOI] [PubMed] [Google Scholar]
  12. Schwartz J. H., Finn J. T., Vaughan G., Steinmetz P. R. Distribution of metabolic CO2 and the transported ion species in acidification by turtle bladder. Am J Physiol. 1974 Feb;226(2):283–289. doi: 10.1152/ajplegacy.1974.226.2.283. [DOI] [PubMed] [Google Scholar]
  13. Schwartz J. H. H+ current response to CO2 and carbonic anhydrase inhibition in turtle bladder. Am J Physiol. 1976 Aug;231(2):565–572. doi: 10.1152/ajplegacy.1976.231.2.565. [DOI] [PubMed] [Google Scholar]
  14. Schwartz J. H., Rosen S., Steinmetz P. R. Carbonic anhydrase function and the epithelial organization of H+ secretion in turtle urinary bladder. J Clin Invest. 1972 Oct;51(10):2653–2662. doi: 10.1172/JCI107083. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Schwartz J. H., Steinmetz P. R. CO2 requirements for H+ secretion by the isolated turtle bladder. Am J Physiol. 1971 Jun;220(6):2051–2057. doi: 10.1152/ajplegacy.1971.220.6.2051. [DOI] [PubMed] [Google Scholar]
  16. Steinmetz P. R. Acid-base relations in epithelium of turtle bladder: site of active step in acidification and role of metabolic CO2. J Clin Invest. 1969 Jul;48(7):1258–1265. doi: 10.1172/JCI106091. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Steinmetz P. R. Cellular mechanisms of urinary acidification. Physiol Rev. 1974 Oct;54(4):890–956. doi: 10.1152/physrev.1974.54.4.890. [DOI] [PubMed] [Google Scholar]
  18. Steinmetz P. R. Characteristics of hydrogen ion transport in urinary bladder of water turtle. J Clin Invest. 1967 Oct;46(10):1531–1540. doi: 10.1172/JCI105644. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Steinmetz P. R., Cohen L. H., Husted R. F., Mueller A. Functional organization of proton and bicarbonate transport in turtle urinary bladder. Ann N Y Acad Sci. 1980;341:77–89. doi: 10.1111/j.1749-6632.1980.tb47162.x. [DOI] [PubMed] [Google Scholar]
  20. Steinmetz P. R., Lawson L. R. Effect of luminal pH on ion permeability and flows of Na+and H+ in turtle bladder. Am J Physiol. 1971 Jun;220(6):1573–1580. doi: 10.1152/ajplegacy.1971.220.6.1573. [DOI] [PubMed] [Google Scholar]
  21. Steinmetz P. R., Omachi R. S., Frazier H. S. Independence of hydrogen ion secretion and transport of other electrolytes in turtle bladder. J Clin Invest. 1967 Oct;46(10):1541–1548. doi: 10.1172/JCI105645. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Struyvenberg A., Morrison R. B., Relman A. S. Acid-base behavior of separated canine renal tubule cells. Am J Physiol. 1968 May;214(5):1155–1162. doi: 10.1152/ajplegacy.1968.214.5.1155. [DOI] [PubMed] [Google Scholar]
  23. Thomas R. C. The effect of carbon dioxide on the intracellular pH and buffering power of snail neurones. J Physiol. 1976 Mar;255(3):715–735. doi: 10.1113/jphysiol.1976.sp011305. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. WADDELL W. J., BUTLER T. C. Calculation of intracellular pH from the distribution of 5,5-dimethyl-2,4-oxazolidinedione (DMO); application to skeletal muscle of the dog. J Clin Invest. 1959 May;38(5):720–729. doi: 10.1172/JCI103852. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Waddell W. J., Bates R. G. Intracellular pH. Physiol Rev. 1969 Apr;49(2):285–329. doi: 10.1152/physrev.1969.49.2.285. [DOI] [PubMed] [Google Scholar]
  26. Willsky G. R. Characterization of the plasma membrane Mg2+-ATPase from the yeast, Saccharomyces cerevisiae. J Biol Chem. 1979 May 10;254(9):3326–3332. [PubMed] [Google Scholar]

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