Tityustoxin-mediated Na+ influx is more efficient than KCl depolarisation in promoting Ca2+-dependent glutamate release from synaptosomes
| Autor: | Marcus Vinicius Gomez, Michael Brammer, R. Ribeiro-Santos, Tasso Moraes-Santos, Marco Aurélio Romano-Silva |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Neurotoxins
Glutamic Acid Scorpion Venoms Tetrodotoxin In Vitro Techniques Potassium Chloride Tityustoxin chemistry.chemical_compound Glutamates Animals Channel blocker Rats Wistar Ion transporter Cerebral Cortex Synaptosome General Neuroscience Sodium Glutamate receptor Depolarization Glutamic acid Rats chemistry Biochemistry Neuromuscular Depolarizing Agents Biophysics Calcium Synaptosomes |
| Zdroj: | Neuroscience Letters. 169:90-92 |
| ISSN: | 0304-3940 |
| Popis: | The scorpion venom toxin, tityustoxin (TsTX), causes rapid, dose-dependent increases in intracellular free Ca2+ ([Ca2+]i) and glutamate release in rat cerebrocortical synaptosomes. These effects are completely abolished by the Na+ channel blocker tetrodotoxin (TTX). The increase in [Ca2+]i is completely dependent on extracellular Ca2+ but the increased glutamate release has both Ca(2+)-dependent and -independent components. Comparison of the effects of TsTX with those of depolarising concentrations of KCl reveals that TsTX is more effective, both in raising [Ca2+]i and promoting Ca(2+)-dependent and -independent glutamate release. These data suggest that the Ca(2+)-dependent glutamate release caused by TsTX is only partly due to Ca2+ entry through voltage-sensitive Ca2+ channels. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|