title: Nitric oxide-mediated arachidonic acid release from perifused Venus verrucosa oocytes.
abstract: This study was undertaken in order to investigate the possible interactions between nitric oxide and arachidonic acid (AA) in Venus verrucosa oocytes. We perifused isolated oocytes to determine the effect of the following substances on [3H]arachidonic acid release ([3H]AA): (1) A 23187, a calcium ionophore; (2) nitric oxide (NO) donors; (3) 1,1,1-trifluoromethyl-6,9,12,15 heicosatetraen-2-one (AACOCF(3)), a specific phospholipase A(2) (PLA(2)) inhibitor; (4) [5'-hydroxymethyl-2'-furyl]-1-benzyl indazole (YC-1) and 1H-[1,2,4]oxadiazolo[4,3-alpha]quinoxalin-1-one (ODQ), specific soluble guanylyl cyclase activator and inhibitor, respectively; (5) L-arginine, the substrate of nitric oxide synthase; (6) L-nitroarginine methyl esther (L-NAME), an inhibitor of nitric oxide synthase. Our results demonstrated that: (a) the calcium ionophore dose-dependently increased [3H]arachidonic acid release; (b) the NO donors sodium nitroprusside (SNP) and linsidomine (SIN-1) highly increased [3H]arachidonic acid output, while S-nitroso-N-acetylpenicillamine (SNAP) was without effect; (c) AACOCF(3) completely blocked the [3H]arachidonic acid release induced by SNP and SIN-1; (d) YC-1 increased [3H]arachidonic acid release, while ODQ completely counteracted SNP response; (e) [3H]arachidonic acid output was also increased by L-arginine; (f) a similar effect was, paradoxically, obtained in the presence of L-NAME. Furthermore, using RT-PCR we demonstrated in the same cells the presence of a nitric oxide synthase (NOS) mRNA, whose expression was not modulated by interleukin 1beta (IL-1beta). These results demonstrate the presence of a both calcium-dependent and NO-sensitive PLA(2) and of nitric oxide synthase in V. verrucosa oocytes. Our data also suggest a co-action of the two pathways in the control of reproduction in this bivalve.
authors.affiliation: Department of Biology, General Physiology Section, University of Ferrara, via Luigi Borsari, 46, Ferrara I-44100, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Barbin
authors.forename: Isabella
authors.initials: I
authors.lastname: Boarini
authors.forename: Pier Giorgio
authors.initials: PG
authors.lastname: Borasio
authors.forename: Paola
authors.initials: P
authors.lastname: Barion
authors.forename: Sara
authors.initials: S
authors.lastname: Fiorini
authors.forename: Remigio
authors.initials: R
authors.lastname: Rossi
authors.forename: Carla
authors.initials: C
authors.lastname: Biondi
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D049872:Bivalvia / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D008563:Membrane Lipids / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism; D012098:Reproduction / Q000502:physiology
chemical_list: D008563:Membrane Lipids; D020030:Nitric Oxide Donors; D016718:Arachidonic Acid; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D010741:Phospholipases A; D002118:Calcium