title: Stimulation of arachidonic acid release by vasopressin in A7r5 vascular smooth muscle cells mediated by Ca2+-stimulated phospholipase A2.
abstract: Arachidonic acid (AA) regulates many aspects of vascular smooth muscle behaviour, but the mechanisms linking receptors to AA release are unclear. In A7r5 vascular smooth muscle cells pre-labelled with (3)H-AA, vasopressin caused a concentration-dependent stimulation of 3H-AA release that required phospholipase C and an increase in cytosolic [Ca2+]. Ca2+ release from intracellular stores and Ca2+ entry via L-type channels or the capacitative Ca2+ entry pathway were each effective to varying degrees. Selective inhibitors of PLA2 inhibited the 3H-AA release evoked by vasopressin, though not the underlying Ca2+ signals, and established that cPLA2 mediates the release of AA. We conclude that in A7r5 cells vasopressin stimulates AA release via a Ca2+-dependent activation of cPLA2.
authors.affiliation: Department of Pharmacology, Tennis Court Road, Cambridge CB2 1PD, UK.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Liu
authors.forename: Colin W
authors.initials: CW
authors.lastname: Taylor
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects*; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000201:enzymology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000201:enzymology* / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D051381:Rats; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014667:Vasopressins / Q000494:pharmacology*
chemical_list: D020746:Calcium Channels, L-Type; D014662:Vasoconstrictor Agents; D014667:Vasopressins; D016718:Arachidonic Acid; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium