Characterization of chloride currents and their noradrenergic modulation in rat taste receptor cells
| Autor: | Xiao-Dong Sun, M. Scott Herness |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
4-Acetamido-4'-isothiocyanatostilbene-2
2'-disulfonic Acid Patch-Clamp Techniques Nifedipine Physiology Chemistry General Neuroscience Isoproterenol Niflumic Acid 4 4'-Diisothiocyanostilbene-2 2'-Disulfonic Acid Adrenergic beta-Agonists In Vitro Techniques Taste Buds Chloride Propranolol Cell biology Membrane Potentials Rats Taste receptor Chloride Channels Taste medicine Animals Transduction (physiology) medicine.drug Cadmium |
| Zdroj: | Journal of neurophysiology. 82(1) |
| ISSN: | 0022-3077 |
| Popis: | Taste receptor cells contain a heterogeneous array of voltage-dependent ion conductances that are essential components for the transduction of gustatory stimuli. Although mechanistic roles have been proposed for several cationic conductances, the understanding of anionic currents is rudimentary. This study characterizes biophysical and pharmacological properties of chloride currents in rat posterior taste cells using whole cell patch-clamp recording technique. Taste cells express a heterogeneous array of chloride currents that displayed strong outward rectification, contained both calcium–dependent and calcium–independent components, and achieved a maximal conductance of almost 1 nS. Reversal potentials altered predictably with changes in chloride concentration. Currents were sensitive to inhibition by the chloride channel pharmacological agents DIDS, SITS, and niflumic acid but were insensitive to 9-AC. Adrenergic enhancement of chloride currents, present in other cell types, was tested on taste cells with the β-adrenergic agonist isoproterenol (ISP). ISP enhanced the outwardly rectifying portion of the chloride current. This enhancement was calcium dependent and was blocked by the β-adrenergic antagonist propranolol. Collectively these observations suggest that chloride currents may participate not only in usually ascribed functions such as stabilization of the membrane potential and volume regulation but additionally play active modulatory roles in the transduction of gustatory stimuli. |
| Databáze: | OpenAIRE |
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