The application of electron microprobe analysis to biological tissues allows the determination of electrolytes within individual cells or even subcellular structures. This capability enables the elucidation of the transport pathways for different electrolytes in different cell types of an epithelium. One way to clarify transepithelial cellular transport routes of ions is the exchange of the ions in question against marker ions which are not common in biological fluids but which are similarly transported. If the marker ion is added to that side of the epithelium from which the flux originates those cells involved in the transport should be marked. Furthermore marker ions can also be used to elucidate complex transport processes, such as cotransports, across a single cell membrane. During recent years we have used the markers Br and Rb to characterize transport mechanisms in several epithelial tissues. Rb instead of K was employed to elucidate the transport characteristics of a basolaterally located electrolyte cotransport system involved in cellular volume regulation of amphibian skins. Br was substituted for Cl in the apical and basal bathing solutions of toad skin to gain further information on the route of trans-cellular Cl transport. Using Rb in the luminal bathing solution of rabbit urinary bladder, it was possible to localize the Na transport compartment in this multilayered epithelium.
Apical Side Frog Skin Basal Side Amphibian Skin Multilayered Epithelium
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Bauer R, Rick R (1978) Computer analysis of X-ray spectra (EDS) from thin biological specimens. X-ray Spectrom 7:63–69.CrossRefGoogle Scholar
Clausen C, Lewis SA, Diamond JM (1979) Impedance analysis of a tight epithelium using a distributed resistance model. Biophys J 26:291–318.PubMedCrossRefGoogle Scholar
Dörge A, Rick R, Gehring K, Thurau K (1978) Preparation of freeze-dried cryosections for quantitative X-ray microanalysis of electrolytes in biological soft tissues. Pflügers Arch. 373:85–97.PubMedCrossRefGoogle Scholar
Dörge A, Rick R, Beck F, Thurau K (1985) Cl transport across the basolateral membrane in frog skin epithelium. Pflügers Arch. 405:S8–S11.PubMedCrossRefGoogle Scholar
Ferreira KTG, Ferreira HG (1981) The regulation of volume and ion composition in frog skin. Biochim Biophys Acta 646:193–202.PubMedCrossRefGoogle Scholar
Harck AF, Larsen EH (1986) Concentration dependence of halide fluxes and selectivity of the anion pathway in toad skin. Acta Physiol Scand 128:289–304.PubMedCrossRefGoogle Scholar
Larsen EH (1982) Chloride current rectification in toad skin. In: Zadunaisky J (ed) Chloride transport in biological membranes. Academic Press, Inc, New York, p 333–364.Google Scholar
Larsen EH, Rasmussen BE (1985) A mathematical model of amphibian skin epithelium with two types of transporting cellular units. Pflügers Arch 405:S50–S58.PubMedCrossRefGoogle Scholar
Larsen EH, Ussing HH, Spring KR (1987) Ion transport by mitochondria-rich cells in toad skin. J Membrane Biol 1:25–40.CrossRefGoogle Scholar
Lewis SA, Eaton DC, Diamond JM (1976) The mechanism of Na+ transport by rabbit urinary bladder. J Membrane Biol 28:41–70.CrossRefGoogle Scholar
Lewis SA, Eaton DC, Clausen C, Diamond JM (1977) Nystatin as a probe for investigating the electrical properties of a tight epithelium. J Gen Physiol 70:427–440.PubMedCrossRefGoogle Scholar
Lewis SA, Hanrahan JW (1985) Apical and basolateral membrane ionic channels in rabbit urinary bladder epithelium. Pflügers Arch. 405:S83–S88.PubMedCrossRefGoogle Scholar
Rick R, Dörge A, v Arnim E, Thurau K (1978) Electron microprobe analysis of frog skin epithelium: Evidence for a syncytial sodium transport compartment. J Membrane Biol 39:313–331.CrossRefGoogle Scholar
Ussing HH (1965) Relationship between osmotic reactions and active sodium transport in the frog skin epithelium. Acta Physiol Scand 63:141–155.PubMedCrossRefGoogle Scholar