Differential effects of bupivacaine and tetracaine on capsaicin-induced currents in dorsal root ganglion neurons
| Autor: | Thomas S. McDowell, Hirochika Komai |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Male
Patch-Clamp Techniques Tetracaine TRPV1 Pharmacology Article Membrane Potentials Rats Sprague-Dawley chemistry.chemical_compound Dorsal root ganglion Ganglia Spinal Noxious stimulus medicine Animals Drug Interactions Patch clamp Anesthetics Local Cells Cultured Neurons Dose-Response Relationship Drug Chemistry General Neuroscience Bupivacaine Rats medicine.anatomical_structure nervous system Animals Newborn Capsaicin Anesthesia Nociceptor lipids (amino acids peptides and proteins) Female Neuron medicine.drug |
| Zdroj: | Neuroscience letters. 380(1-2) |
| ISSN: | 0304-3940 |
| Popis: | Capsaicin opens the TRPV1 channel, a cation channel that depolarizes and activates nociceptive neurons. Following this initial activation, neurons become desensitized to subsequent applications of capsaicin as well as to other noxious stimuli, a phenomenon attributed primarily to the entry of Ca2+ ions through the open TRPV1 channel. This ability of capsaicin to desensitize nociceptors has led to its use as an analgesic in the treatment of a variety of chronic pain states. Because treatment with capsaicin is initially quite painful, local anesthetics are sometimes used to block axonal conduction in nociceptive neurons and thus minimize pain. However, local anesthetics might also block TRPV1 and prevent the Ca2+ entry required for capsaicin-induced desensitization. We have studied the direct effect of local anesthetics on currents induced by capsaicin (1 microM) in acutely isolated rat dorsal root ganglion neurons using the whole cell patch clamp technique. At the highest concentration tested (1 mM), bupivacaine only moderately inhibited the capsaicin-induced current to 55 +/- 27% of control (mean +/- S.D.; n=12, p |
| Databáze: | OpenAIRE |
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