A new approach to measuring transepithelial potentials in the bovine lens reveals a chloride-dependent component
| Autor: | T. J. C. Jacob, Jin Jun Zhang |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Intracellular Fluid
Cell Membrane Permeability In Vitro Techniques Ouabain Epithelium Membrane Potentials chemistry.chemical_compound Chlorides Chloride Channels Benzamil Lens Crystalline medicine Animals Channel blocker Transepithelial potential difference Ion Transport Sodium Furosemide General Medicine Anatomy Amiloride Electrophysiology medicine.anatomical_structure chemistry Lens (anatomy) Nitrobenzoates Biophysics Potassium Cattle Sodium-Potassium-Exchanging ATPase medicine.drug |
| Zdroj: | Experimental physiology. 79(5) |
| ISSN: | 0958-0670 |
| Popis: | A new approach was used to measure anterior and posterior potentials and resistances of the bovine lens. Segments of the anterior, central and posterior lens were studied by mounting a disc of tissue from either the front or the back of the lens in a double chamber. At 35 degrees C the isolated anterior epithelial preparation exhibited a high potential of 9 mV and a low resistance of 279 omega cm2. The lens epithelium can therefore be classified as a ‘leaky’ or low resistance epithelium. Amiloride, benzamil and furosemide (frusemide) all reduced the anterior transepithelial potential and increased the resistance, amphotericin B (aqueous side) abolished the potential, whereas SITS (4-acetamido-4'-isothiocyanatostilbene-2,2'-disulphonic acid) had no effect. The posterior lens preparation was found to have a ‘transepithelial’ of -4 mV. This potential and a proportion of the anterior potential were not sensitive to ouabain, amiloride, furosemide, Na+ removal or raised K+, but were abolished by lowering [Cl-] and reduced by the Cl- channel blocker NPPB. We conclude that chloride plays a significant role in the maintenance of transepithelial potentials at both the anterior and posterior surfaces of the lens. |
| Databáze: | OpenAIRE |
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