Ins(1,4,5)P3 formation and fluctuating chloride current response induced by external ATP in Xenopus oocytes injected with embryonic guinea pig brain mRNA
| Autor: | Eric Honoré, Thibault Collin, Pierre Guilbault, Franck Fournier |
|---|---|
| Jazyk: | angličtina |
| Předmět: |
Adenosine
Microinjections Guinea Pigs Biophysics Xenopus Inositol 1 4 5-Trisphosphate In Vitro Techniques Biochemistry Guinea pig Xenopus laevis chemistry.chemical_compound Adenosine Triphosphate Extracellular ATP Chlorides Structural Biology Guinea pig brain mRNA Gallic Acid Genetics medicine Extracellular Animals RNA Messenger P2 purinoceptor Molecular Biology biology Internal Ca2+ pool Electric Conductivity Receptors Purinergic Brain Cell Biology Neomycin biology.organism_classification Molecular biology Adenosine Monophosphate Cell biology Adenosine Diphosphate EGTA chemistry Ins(1 4 5)P3 Liberation Calcium Xenopus oocyte Intracellular medicine.drug |
| Zdroj: | FEBS Letters. (1-2):205-208 |
| ISSN: | 0014-5793 |
| DOI: | 10.1016/0014-5793(90)80845-A |
| Popis: | In voltage-clamped Xenopus oocytes injected with embryonic guinea pig mRNA, effective concentrations of extracellular ATP elicited an inward fluctuating current. This current, carried by Cl-ions, was mainly dependent upon liberation of Ca2+ ions from stores as demonstrated by experiments using intracellular EGTA loading and TMB-8 superfusion. Neomycin inhibited these fluctuating currents indicating that the transplanted purinoceptor is linked to phospholipase C activity and triggers Ins(1,4,5)P3 formation. Ins(1,4,5)P3 production evoked by external ATP was clearly demonstrated by directly measuring the water-soluble Ins(1,4,5)P3 level in injected oocytes. Finally, it is suggested that the ATP effect was mediated by a Ca2+ release from Ins(1,4,5)P3 sensitive pools since heparin blocked the ATP responsiveness. The acquired purinoceptor may be made apparent to a P2 subtype since ATP and ADP were equipotent in eliciting Cl− current while AMP and Adenosine were ineffective in injected oocytes. |
| Databáze: | OpenAIRE |
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