title: Inflammatory oedema induced by Lachesis muta muta (Surucucu) venom and LmTX-I in the rat paw and dorsal skin.
abstract: The ability of crude venom and a basic phospholipase A(2) (LmTX-I) from Lachesis muta muta venom to increase the microvascular permeability in rat paw and skin was investigated. Crude venom or LmTX-I were injected subplantarly or intradermally and rat paw oedema and dorsal skin plasma extravasation were measured. Histamine release from rat peritoneal mast cell was also assessed. Crude venom or LmTX-I induced dose-dependent rat paw oedema and dorsal skin plasma extravasation. Venom-induced plasma extravasation was inhibited by the histamine H(1) antagonist mepyramine (6mg/kg), histamine/5-hydroxytriptamine antagonist cyproheptadine (2mg/kg), cyclooxygenase inhibitor indomethacin (5mg/kg), nitric oxide synthesis inhibitor l-NAME (100nmol/site), tachykinin NK(1) antagonist SR140333 (1nmol/site) and bradykinin B(2) receptor antagonist Icatibant (0.6mg/kg). Platelet-activating factor (PAF) antagonist PCA4248 (5mg/kg) had no effect. LmTX-I-induced skin extravasation was inhibited by cyproheptadine, mepyramine, indomethacin and PCA4248, while l-NAME and SR140333 had no effect. Additionally, both Lachesis muta muta venom and LmTX-I concentration-dependently induced histamine release from rat mast cells. In conclusion, Lachesis muta muta venom and LmTX-I increase microvascular permeability by mechanisms involving in vivo mast cell activation and arachidonic acid metabolites. Additionally, crude venom-induced responses also involve substance P, nitric oxide and bradykinin release, whether LmTX-I-induced responses involve PAF.
authors.affiliation: Department of Pharmacology, Faculty of Medical Sciences (FCM), UNICAMP, PO Box 6111, 13084-971 Campinas, SP, Brazil.
authors.forename: Tatiane
authors.initials: T
authors.lastname: Ferreira
authors.forename: Enilton A
authors.initials: EA
authors.lastname: Camargo
authors.forename: Maria Teresa C P
authors.initials: MT
authors.lastname: Ribela
authors.forename: Daniela C
authors.initials: DC
authors.lastname: Damico
authors.forename: Sérgio
authors.initials: S
authors.lastname: Marangoni
authors.forename: Edson
authors.initials: E
authors.lastname: Antunes
authors.forename: Gilberto
authors.initials: G
authors.lastname: De Nucci
authors.forename: Elen C T
authors.initials: EC
authors.lastname: Landucci
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D003435:Crotalid Venoms / Q000633:toxicity*; D004487:Edema / Q000139:chemically induced*; D005528:Foot / Q000473:pathology*; D007249:Inflammation / Q000139:chemically induced*; D008407:Mast Cells / Q000187:drug effects / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D051381:Rats; D043782:Receptor, Bradykinin B2 / Q000378:metabolism; D018039:Receptors, Tachykinin / Q000378:metabolism; D012867:Skin / Q000187:drug effects* / Q000473:pathology; D017819:Viperidae / Q000502:physiology
chemical_list: D003435:Crotalid Venoms; C072644:Lachesis venom; D043782:Receptor, Bradykinin B2; D018039:Receptors, Tachykinin; D009569:Nitric Oxide; D011451:Prostaglandin-Endoperoxide Synthases