title: Kininogenase activity of Thalassophryne nattereri fish venom.
abstract: Accidents caused by the venomous fish Thalassophryne nattereri are characterized by edema, intense pain and necrosis at the site of the sting. This study assessed the nociceptive and edematogenic activities of T. nattereri venom after injection into the mouse hindpaw and determination of the paw licking duration and weight. Subplantar injections of the venom (0.1-6 microg) induced a dose-related increase of the paw licking time and paw swelling with maximal values at 3 microg (209.5 +/- 57.5 s and 135.0 +/- 6.8 mg, respectively). Pretreatment of mice with either indomethacin (10 mg/kg, i.p.), a cyclooxygenase inhibitor, dexamethasone (1 mg/kg, s.c.), a steroid anti-inflammatory agent, cyproheptadine (1 mg/kg, i.p.), antagonist of serotonin receptors or L-NAME (100 mg/kg, s.c.), inhibitor of nitric oxide syntase, did not affect the venom-induced nociceptive and edematogenic responses. Injection of the opioid analgesic fentanyl (0.1 mg/kg, s.c.) reduced the paw licking time induced by 1 microg venom by 84% of control, without affecting the paw swelling. Both nociceptive and edematogenic responses were reduced after treatment with a specific tissue kallikrein inhibitor (TKI, 100 mg/kg, i.p.) by 78% and 24% from control values, respectively. Administration of a specific plasma kallikrein inhibitor (PKSI(527,) 100 mg/kg, s.c.) did not affect the venom-induced nociceptive response, but it decreased the paw edema by 15% from control. After injection of the angiotensin-converting enzyme inhibitor captopril (100 mg/kg, i.p.) the venom-induced nociceptive end edematogenic responses were increased by two-fold. The role of kallikreins possibly present in the venom was further assessed by hydrolysis of human kininogen and kininogen-derived synthetic peptides, showing the release of kallidin (Lys-bradykinin). The hydrolysis was inhibited by metal chelating agents but not by serino-, aspartyl- or cysteino-proteinase inhibitors. The data suggest that a protease with tissue-kallikrein-like activity plays a major role in nociception and edema induced by T. nattereri venom and this should be considered to achieve efficient treatments for human accidents with this venom.
authors.affiliation: Laboratory of Immunopathology-Instituto Butantan, Avenida Vital Brasil, 1500, Butantan, 05503 900 São Paulo, SP, Brazil.
authors.forename: Mônica
authors.initials: M
authors.lastname: Lopes-Ferreira
authors.forename: José Artur da Silva
authors.initials: JA
authors.lastname: Emim
authors.forename: Vitor
authors.initials: V
authors.lastname: Oliveira
authors.forename: Luciano
authors.initials: L
authors.lastname: Puzer
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Cezari
authors.forename: Mariana da Silva
authors.initials: Mda S
authors.lastname: Araújo
authors.forename: Luiz
authors.initials: L
authors.lastname: Juliano
authors.forename: Antônio José
authors.initials: AJ
authors.lastname: Lapa
authors.forename: Caden
authors.initials: C
authors.lastname: Souccar
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Moura-da-Silva
mesh_terms: D000818:Animals; D024541:Batrachoidiformes; D005397:Fish Venoms / Q000201:enzymology* / Q000494:pharmacology; D007610:Kallikreins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007704:Kininogens / Q000378:metabolism; D007705:Kinins / Q000378:metabolism; D008297:Male; D051379:Mice; D010147:Pain Measurement
chemical_list: D005397:Fish Venoms; D007704:Kininogens; D007705:Kinins; D007610:Kallikreins