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Role of iPLA2 and store-operated channels in agonist-induced Ca2+ influx and constriction in cerebral, mesenteric, and carotid arteries.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Park, Kristen M. Trucillo, Mario P. Serban, Nicolas Cohen, Richard Alan |
| Copyright Year | 2008 |
| Abstract | Store-operated channels (SOC) and store-operated Ca2+ entry are known to play a major role in agonist-induced constriction of smooth muscle cells (SMC) in conduit vessels. In microvessels the role of SOC remains uncertain, in as much as voltage-gated L-type Ca2+ (Ca2+L) channels are thought to be fully responsible for agonist-induced Ca2+ influx and vasoconstriction. We present evidence that SOC and their activation via a Ca2+-independent phospholipase A2 (iPLA2)-mediated pathway play a crucial role in agonist-induced constriction of cerebral, mesenteric, and carotid arteries. Intracellular Ca2+ in SMC and intraluminal diameter were measured simultaneously in intact pressurized vessels in vitro. We demonstrated that 1) Ca2+ and contractile responses to phenylephrine (PE) in cerebral and carotid arteries were equally abolished by nimodipine (a Ca2+L) inhibitor) and 2-aminoethyl diphenylborinate (an inhibitor of SOC), suggesting that SOC and Ca2+L channels may be involved in agonist-induced constriction of cerebral arteries, and 2) functional inhibition of iPLA2beta totally inhibited PE-induced Ca2+ influx and constriction in cerebral, mesenteric, and carotid arteries, whereas K+-induced Ca2+ influx and vasoconstriction mediated by Ca2+L channels were not affected. Thus iPLA2-dependent activation of SOC is crucial for agonist-induced Ca2+ influx and vasoconstriction in cerebral, mesenteric, and carotid arteries. We propose that, on PE-induced depletion of Ca2+ stores, nonselective SOC are activated via an iPLA2-dependent pathway and may produce a depolarization of SMC, which could trigger a secondary activation of Ca2+L channels and lead to Ca2+ entry and vasoconstriction. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://ajpheart.physiology.org/content/ajpheart/294/3/h1183.full.pdf |
| Alternate Webpage(s) | http://ajpheart.physiology.org/content/ajpheart/294/3/H1183.full.pdf |
| PubMed reference number | 18156193v1 |
| Volume Number | 294 |
| Issue Number | 3 |
| Journal | American journal of physiology. Heart and circulatory physiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Arterial system Blood Vessel CA2 field Calcium ion Calcium-Independent Phospholipase A2 Carotid Arteries Diameter (qualifier value) In Vitro [Publication Type] Mesentery Microvessels Muscle Cells Myocytes, Smooth Muscle N-type calcium channels Nimodipine PLA2G6 gene Phenylephrine Smooth muscle (tissue) Structure of cerebral artery Vascular constriction (function) phosphoethanolamine |
| Content Type | Text |
| Resource Type | Article |
