RESUMO
A haemorrhagic protein toxin (SA-HT) was isolated and purified from the spine extract of the Indian venomous butterfish, S. argus Linn, by two step ion exchange chromatography. The toxin was homogeneous in native and SDS-PAGE gel. SDS-molecular weight of the toxin was found to be 18.1 +/- 0.09 kDa. SA-HT produced severe haemorrhage on stomach wall but devoid of cutaneous haemorrhage. UV, EDTA, trypsin, protease, cyproheptadine, indomethacin, acetylsalicylic acid and BW755C treatment significantly antagonized the haemorrhagic activity of SA-HT. The toxin produced dose and time dependent oedema on mice hind paw, which was significantly encountered by cyproheptadine, indomethacin and BW755C. SA-HT increased capillary permeability on guinea pig dorsal flank. On isolated guineapig ileum, rat fundus and uterus, SA-HT produced slow contraction which was completely antagonised by prostaglandin blocker SC19220. On isolated rat duodenum, SA-HT produced slow relaxation. SA-HT significantly increased plasma plasmin, serum MDA level and decreased serum SOD level indicating the possible involvement of cyclooxygenase and lipooxygenase pathway.
Assuntos
4,5-Di-Hidro-1-(3-(Trifluormetil)Fenil)-1H-Pirazol-3-Amina/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Capilares , Cromatografia por Troca Iônica , Ciproeptadina/farmacologia , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Ácido Edético/farmacologia , Eletroforese em Gel de Poliacrilamida , Feminino , Proteínas de Peixes/química , Venenos de Peixe/química , Fármacos Gastrointestinais/farmacologia , Cobaias , Indometacina/farmacologia , Lipoxigenase/metabolismo , Camundongos , Músculo Liso/efeitos dos fármacos , Perciformes , Permeabilidade , Ratos , Coluna Vertebral/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Tripsina/farmacologia , Raios Ultravioleta , Útero/efeitos dos fármacosRESUMO
A lethal cardiotoxic (BO-CT; Bidder's organ cardiotoxin) protein was purified from the Bidder's organ of the common Indian toad B. melanostictus by gel filtration on Sephadex G-200. The homogeneity of cardiotoxin was tested by gel electrophoresis. The molecular weight of lethal BO-CT was 62 KDa and was devoid of glycoprotein. LD50 of the BO-CT was 50 micrograms/20 g (i.v.) in male albino mice. On isolated heart and auricle BO-CT initially increased the rate and amplitude of contraction and finally produced irreversible blockade of contraction. BO-CT induced auricular blockade, was not influenced by verapamil, propranolol and atropine. On isolated chick biventer cervicis preparation BO-CT produced irreversible blockade of electrically induced twitch response followed by contracture. This action was not antagonized by 4-aminopyridine and neostigmine. BO-CT induced contracture on chick biventer cervicis was increased by Ca2+, decreased by Na+ and abolished by K+. Cardiotoxic and neuromuscular activity of BO-CT was heat stable and abolished by proteolytic enzyme.