Ação do veneno da aranha Pheneutria nigrivente em musculo liso vascular de coelho




The effects produced by Phoneutria nigriventer("armed spider") venom (PNV) in rabbit vascular smooth musc1e have been investigated. De endothelialized vascular strips were superfused in a cascade system with oxygenated (95% O2 /5% C02) and warmed (37°C) Krebs solution at 5 rnl/min. PNV (0.3-30 µg) produced dose-dependent contractions in both venous and arterial tissues (cava, mesenteric and jugular veins and puImonazy, mesenteric and coeliac arteries, respectively). Methysergide did not s1gniflcantly a:ffect PNV-induced contractions in venous tissues or Í Il puImonazy artery ind1cating that serotonin 1s not involved. Furthermore, d1alysis of the venom for up to 48 h d1d not alter th1s contractile activity. Ne1ther tetrodotoxin nor phenoxybenzamine s1gnificantly affected PNV induced contractlons suggesting that voltage-dependent sodium channel actlvatlon and endogenous catecholamine release from vessel wall autonomic nerve endings are also Í10t involved in the PNV response. The incubatlon with trypsin reduced significantly PNV-induced contractions. suggesting that the venom contains polypeptides Following gel-filtration, 10n-exchange chromatography and trtcine SDS- PAGE electrophoresis of the PNV, 8 fractlons (mw 8-50 kDa) with contractile activity were isolated


aranha - veneno farmacologia

Documentos Relacionados