Mechanisms of [Ca2+]i elevation following P2X receptor activation in the guinea-pig small mesenteric artery myocytes.
In: Pharmacological reports : PR, Jg. 65 (2013), Heft 1, S. 152-63
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Zugriff:
Background: There is growing evidence suggesting involvement of L-type voltage-gated Ca2+ channels (VGCCs) in purinergic signaling mechanisms. However, detailed interplay between VGCCs and P2X receptors in intracellular Ca2+ mobilization is not well understood. This study examined relative contribution of the Ca2+ entry mechanisms and induced by this entry Ca2+ release from the intracellular stores engaged by activation of P2X receptors in smooth muscle cells (SMCs) from the guinea-pig small mesenteric arteries.
Methods: P2X receptors were stimulated by the brief local application of αβ-meATP and changes in [Ca2+]i were monitored in fluo-3 loaded SMCs using fast x-y confocal Ca2+ imaging. The effects of the block of L-type VGCCs and/or depletion of the intracellular Ca2+ stores on αβ-meATP-induced [Ca2+]i transients were analyzed.
Results: Our analysis revealed that Ca2+ entry via L-type VGCCs is augmented by the Ca2+-induced Ca2+ release significantly more than Ca2+ entry via P2X receptors, even though net Ca2+ influxes provided by the two mechanisms are not significantly different.
Conclusions: Thus, arterial SMCs upon P2X receptor activation employ an effective mechanism of the Ca2+ signal amplification, the major component of which is the Ca2+ release from the SR activated by Ca2+ influx via L-type VGCCs. This signaling pathway is engaged by depolarization of the myocyte membrane resulting from activation of P2X receptors, which, being Ca2+ permeable, per se form less effective Ca2+ signaling pathway. This study, therefore, rescales potential targets for therapeutic intervention in purinergic control of vascular tone.
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Mechanisms of [Ca2+]i elevation following P2X receptor activation in the guinea-pig small mesenteric artery myocytes.
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Autor/in / Beteiligte Person: | Sukhanova, KY ; Harhun, MI ; Bouryi, VA ; Gordienko, DV |
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Zeitschrift: | Pharmacological reports : PR, Jg. 65 (2013), Heft 1, S. 152-63 |
Veröffentlichung: | 2020- : Cham, Switzerland : Springer International Publishing ; <i>Original Publication</i>: Kraków, Poland : Institute of Pharmacology, Polish Academy of Sciences, c2005-, 2013 |
Medientyp: | academicJournal |
ISSN: | 2299-5684 (electronic) |
DOI: | 10.1016/s1734-1140(13)70973-3 |
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