Depletion of Ca2+ from intracellular stores potentiates spontaneous contractions of the rat portal vein
| Autor: | Richard P. Burt |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Intracellular Fluid
Male Cations Divalent Calcium-Transporting ATPases In Vitro Techniques Pharmacology Biology Rats Sprague-Dawley Phenylephrine chemistry.chemical_compound Extracellular medicine Animals Calphostin Enzyme Inhibitors Protein kinase C Portal Vein Ryanodine Ryanodine receptor Rats chemistry Biochemistry Vasoconstriction Calcium Caffeine Cyclopiazonic acid Intracellular medicine.drug |
| Zdroj: | European Journal of Pharmacology. 496:109-118 |
| ISSN: | 0014-2999 |
| Popis: | Spontaneous contractions of the rat portal vein were potentiated in magnitude by phenylephrine, cyclopiazonic acid, ryanodine or caffeine. All these drugs can deplete Ca2+ from intracellular stores, which stimulates store-operated cation entry in some tissues. The possibility that depletion of Ca2+ from intracellular stores potentiates the spontaneous contractions was therefore investigated using functional experiments. Phenylephrine or cyclopiazonic acid was added to tissues in Ca2+-free Krebs solution, followed by a 30-min washout. After addition of extracellular Ca2+, the spontaneous contractions were potentiated. This showed the stimulus for potentiating the contractions remained so long as intracellular Ca2+ stores were depleted. Following phenylephrine washout in normal Krebs solution, potentiation of the spontaneous contractions was attenuated with time. This attenuation was abolished by the protein kinase C inhibitor calphostin C. These results show depletion of Ca2+ from intracellular stores potentiates spontaneous contractions of the portal vein. Protein kinase C may inhibit this mechanism. |
| Databáze: | OpenAIRE |
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