Passive Cl- Currents in Toad Skin: Potential Dependence and Relation to Mitochondria-Rich Cell Density
In tight epithelia, like amphibian skin, the net flow of Cl- ions is predominantly passive and reflects the electrochemical potential gradient across the skin. In the present paper, we shall discuss the dependence of the Cl- current on the transepithelial potential difference. Our hypothesis is that the potential provides not only the driving force for the Cl- flux, but controls the Cl- permeability as well. Evidence is also presented that the passive Cl- pathway is localized to a special cell type, the mitochondria-rich cells. Modes of Cl- permeability regulation, which have been discussed in the literature, are briefly reviewed.
KeywordsGranulosum Cell Current Transient Frog Skin Chloride Transport Bufo Bufo
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- Kristensen P (1982) Chloride transport in frog skin. In: Zadunaisky JA (ed) Chloride transport in biological membranes. Academic, New York, p 319–332Google Scholar
- Larsen EH (1982) Chloride current rectification in toad skin epithelium. In: Zadunaisky JA (ed) Chloride transport in biological membranes. Academic, New York, pp 333–364Google Scholar
- Larsen EH, Rasmussen BE (1985) A mathematical model of amphibian skin epithelium with two types of transporting cellular units. Pflüger Arch Eur J Physiol (in press)Google Scholar
- Larsen EH, Rasmussen BE, Willumsen N (1981) Computer model of transporting epithelial cells. Analysis of current-voltage and current-time curves. In: Salanki J (ed) Advances in physiological sciences, vol III. Pergamon, New York, pp 115–127Google Scholar
- Macey RI, Meyers S (1963) Dependence of chloride permeability on sodium in the isolated frog skin. Am J Physiol 204:1095–1099Google Scholar
- Voûte CL, Meier W (1978) The mitochondria rich cell of frog skin as hormone sensitive ‘shunt path’. J Membr Biol 40:141–165Google Scholar