Abstract
Kinetic and electrophysiological studies were carried out to characterize the efflux of HCO3- (or OH-) across the basolateral membrane of the proton-secreting cells of the frog skin epithelium bathed with dilute saline mucosal solutions. In control conditions, the acidification of the mucosal solution (JnH+) was correlated directly with serosal alkalinization. Cl- substitution in the serosal Ringer (by gluconate or methylsulphate ions) induced an inhibition of proton excretion (70% inhibition). Measurements of the basolateral membrane potential with conventional micro-electrodes and of cell Cl- activity (aCli) and proton activity with double-barrelled ion-sensitive micro-electrodes recorded a basolateral membrane depolarization of 5.1 +/- 0.7 mV (n = 12), a decrease in aCli from 14.5 +/- 1.6 mequiv l-1 to 1.8 +/- 0.3 mequiv l-1 (n = 12), and a cell pH increase from 7.18 +/- 0.04 to 7.32 +/- 0.06 (n = 12) after serosal Cl- replacement. 4,4'-diisothiocyanostilbene-2-2'-disulphonic acid (DIDS) (10(-4) M) and meclofenamate (5 X 10(-5) M) inhibit JHn+ by 34% and 53% respectively whereas bumetanide did not block JHn+. Depolarization of the basolateral membrane (2 mM-Ba2+ addition to the serosal solution) did not block proton excretion. We show that cell Cl- activity is maintained at a higher level than that predicted by the equilibrium potential, by a mechanism located at the basolateral membrane of the epithelium since the apical solution was Cl(-)-free. This mechanism is not sensitive to potential changes at the basolateral membrane in the range tested. An electroneutral Cl(-)-HCO3- exchange mechanism is the simplest hypothesis which can account for our results.
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Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aceves J., Erlij D. Sodium transport across the isolated epithelium of the frog skin. J Physiol. 1971 Jan;212(1):195–210. doi: 10.1113/jphysiol.1971.sp009317. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Aickin C. C., Thomas R. C. An investigation of the ionic mechanism of intracellular pH regulation in mouse soleus muscle fibres. J Physiol. 1977 Dec;273(1):295–316. doi: 10.1113/jphysiol.1977.sp012095. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bello-Reuss E. Electrical properties of the basolateral membrane of the straight portion of the rabbit proximal renal tubule. J Physiol. 1982 May;326:49–63. doi: 10.1113/jphysiol.1982.sp014176. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Biagi B., Kubota T., Sohtell M., Giebisch G. Intracellular potentials in rabbit proximal tubules perfused in vitro. Am J Physiol. 1981 Mar;240(3):F200–F210. doi: 10.1152/ajprenal.1981.240.3.F200. [DOI] [PubMed] [Google Scholar]
- Boron W. F., Boulpaep E. L. Intracellular pH regulation in the renal proximal tubule of the salamander. Basolateral HCO3- transport. J Gen Physiol. 1983 Jan;81(1):53–94. doi: 10.1085/jgp.81.1.53. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Boron W. F. Intracellular pH transients in giant barnacle muscle fibers. Am J Physiol. 1977 Sep;233(3):C61–C73. doi: 10.1152/ajpcell.1977.233.3.C61. [DOI] [PubMed] [Google Scholar]
- Burckhardt B. C., Sato K., Frömter E. Electrophysiological analysis of bicarbonate permeation across the peritubular cell membrane of rat kidney proximal tubule. I. Basic observations. Pflugers Arch. 1984 May;401(1):34–42. doi: 10.1007/BF00581530. [DOI] [PubMed] [Google Scholar]
- Cabantchik Z. I., Rothstein A. The nature of the membrane sites controlling anion permeability of human red blood cells as determined by studies with disulfonic stilbene derivatives. J Membr Biol. 1972 Dec 29;10(3):311–330. doi: 10.1007/BF01867863. [DOI] [PubMed] [Google Scholar]
- Cassola A. C., Mollenhauer M., Frömter E. The intracellular chloride activity of rat kidney proximal tubular cells. Pflugers Arch. 1983 Dec;399(4):259–265. doi: 10.1007/BF00652749. [DOI] [PubMed] [Google Scholar]
- Chan Y. L., Biagi B., Giebisch G. Control mechanisms of bicarbonate transport across the rat proximal convoluted tubule. Am J Physiol. 1982 May;242(5):F532–F543. doi: 10.1152/ajprenal.1982.242.5.F532. [DOI] [PubMed] [Google Scholar]
- 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]
- Cousin J. L., Motais R. Inhibition of anion permeability by amphiphilic compounds in human red cell: evidence for an interaction of niflumic acid with the band 3 protein. J Membr Biol. 1979 Apr 20;46(2):125–153. doi: 10.1007/BF01961377. [DOI] [PubMed] [Google Scholar]
- Ehrenfeld J., Garcia-Romeu F. Active hydrogen excretion and sodium absorption through isolated frog skin. Am J Physiol. 1977 Jul;233(1):F46–F54. doi: 10.1152/ajprenal.1977.233.1.F46. [DOI] [PubMed] [Google Scholar]
- Ehrenfeld J., Garcia-Romeu F. Coupling between chloride absorption and base excretion in isolated skin of Rana esculenta. Am J Physiol. 1978 Jul;235(1):F33–F39. doi: 10.1152/ajprenal.1978.235.1.F33. [DOI] [PubMed] [Google Scholar]
- Ehrenfeld J., Garcia-Romeu F., Harvey B. J. Electrogenic active proton pump in Rana esculenta skin and its role in sodium ion transport. J Physiol. 1985 Feb;359:331–355. doi: 10.1113/jphysiol.1985.sp015588. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ferreira K. T., Ferreira H. G. The regulation of volume and ion composition in frog skin. Biochim Biophys Acta. 1981 Aug 20;646(2):193–202. doi: 10.1016/0005-2736(81)90325-4. [DOI] [PubMed] [Google Scholar]
- Fischer J. L., Husted R. F., Steinmetz P. R. Chloride dependence of the HCO3 exit step in urinary acidification by the turtle bladder. Am J Physiol. 1983 Nov;245(5 Pt 1):F564–F568. doi: 10.1152/ajprenal.1983.245.5.F564. [DOI] [PubMed] [Google Scholar]
- Harvey B. J., Kernan R. P. Intracellular ion activities in frog skin in relation to external sodium and effects of amiloride and/or ouabain. J Physiol. 1984 Apr;349:501–517. doi: 10.1113/jphysiol.1984.sp015170. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Harvey B. J., Kernan R. P. Sodium-selective micro-electrode study of apical permeability in frog skin: effects of sodium, amiloride and ouabain. J Physiol. 1984 Nov;356:359–374. doi: 10.1113/jphysiol.1984.sp015470. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KOEFOED-JOHNSEN V., USSING H. H. The nature of the frog skin potential. Acta Physiol Scand. 1958 Jun 2;42(3-4):298–308. doi: 10.1111/j.1748-1716.1958.tb01563.x. [DOI] [PubMed] [Google Scholar]
- Kleinman J. G., Ware R. A., Schwartz J. H. Anion transport regulates intracellular pH in renal cortical tissue. Biochim Biophys Acta. 1981 Oct 20;648(1):87–92. doi: 10.1016/0005-2736(81)90127-9. [DOI] [PubMed] [Google Scholar]
- Kristensen P. Chloride transport across isolated frog skin. Acta Physiol Scand. 1972 Mar;84(3):338–346. doi: 10.1111/j.1748-1716.1972.tb05185.x. [DOI] [PubMed] [Google Scholar]
- Nagel W. Inhibition of potassium conductance by barium in frog skin epithelium. Biochim Biophys Acta. 1979 Apr 4;552(2):346–357. doi: 10.1016/0005-2736(79)90289-x. [DOI] [PubMed] [Google Scholar]
- Russell J. M., Boron W. F. Role of choloride transport in regulation of intracellular pH. Nature. 1976 Nov 4;264(5581):73–74. doi: 10.1038/264073a0. [DOI] [PubMed] [Google Scholar]
- Sasaki S., Berry C. A. Mechanism of bicarbonate exit across basolateral membrane of the rabbit proximal convoluted tubule. Am J Physiol. 1984 Jun;246(6 Pt 2):F889–F896. doi: 10.1152/ajprenal.1984.246.6.F889. [DOI] [PubMed] [Google Scholar]
- Thomas R. C. Ionic mechanism of the H+ pump in a snail neurone. Nature. 1976 Jul 1;262(5563):54–55. doi: 10.1038/262054a0. [DOI] [PubMed] [Google Scholar]
- Ullrich K. J., Capasso G., Rumrich G., Papavassiliou F., Klöss S. Coupling between proximal tubular transport processes. Studies with ouabain, SITS and HCO3-free solutions. Pflugers Arch. 1977 Apr 25;368(3):245–252. doi: 10.1007/BF00585203. [DOI] [PubMed] [Google Scholar]