The control of chloride conductance in rat parotid isolated acinar cells investigated by photorelease of caged compounds
| Autor: | Peter T. A. Gray, Abdul A. Hassoni |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Male
Carbachol Light Physiology Clinical Biochemistry Analytical chemistry Cell Separation Inositol 1 4 5-Trisphosphate chemistry.chemical_compound Chlorides Physiology (medical) Isoprenaline medicine Animals Parotid Gland Patch clamp Rats Wistar Egtazic Acid Ion transporter Chelating Agents Membrane potential Electric Conductivity Conductance Inositol trisphosphate Adrenergic Agonists Receptors Muscarinic Rats chemistry Biophysics Flash photolysis medicine.drug |
| Zdroj: | Pflugers Archiv : European journal of physiology. 428(3-4) |
| ISSN: | 0031-6768 |
| Popis: | The control of Cl- conductance in rat parotid isolated acinar cells was studied by combined use of whole-cell recording and flash photolysis techniques. Cells were voltage-clamped either at a membrane potential of -40 mV or stepped between -85 mV and 0 mV. Bath-applied carbachol and noradrenaline evoked Cl- current at -85 mV and K+ current at 0 mV. Similar current activations resulted from the photolytic release of either inositol trisphosphate (InsP3) or Ca2+ by a brief near-UV flash. The peak amplitudes of the Cl- conductance (at -85 mV), measured relative to the K+ conductance (at 0 mV), evoked by application of carbachol, noradrenaline or direct manipulation of cytosolic free calcium ([Ca2+]i), were very similar, being 0.56 +/- 0.09 (mean +/- SEM, n = 9), 0.52 +/- 0.01 (n = 7) and 0.46 +/- 0.06 (n = 7). In contrast, the relative amplitude of the Cl- conductance evoked by InsP3 was much larger: 1.49 +/- 0.24 (n = 9). Neither bath application of isoprenaline nor photolysis of "caged" cAMP induced any detectable membrane current. The most probable interpretation of these results is that the observed activation of Cl- conductance by agonists can be explained by the elevation of [Ca2+]i alone. In addition, the present results provide further support for the previously reported suggestion that the Cl- channels and the Ca(2+)-release sites are co-localised [10]. |
| Databáze: | OpenAIRE |
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