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| Durigon,A. M.; Borja-Oliveira,C. R.; Dal Belo,C. A.; Oshima-Franco,Y.; Cogo,J. C.; Lapa,A. J.; Souccar,C.; Rodrigues-Simioni,L.. |
| The pharmacological effects of Bothrops neuwiedi pauloensis venom on mouse phrenic nerve-diaphragm (PND) preparations were studied. Venom (20 mug/ml) irreversibly inhibited indirectly evoked twitches in PND preparations (60 ± 10% inhibition, mean ± SEM; p<0.05; n=6). At 50 mug/ml, the venom blocked indirectly and directly (curarized preparations) evoked twitches in mouse hemidiaphragms. In the absence of Ca2+, venom (50 mug/ml), produced partial blockade only after an 80 min incubation, which reached 40.3 ± 7.8% (p<0.05; n=3) after 120 min. Venom (20 mug/ml) increased (25 ± 2%, p< 0.05) the frequency of giant miniature end-plate potentials in 9 of 10 end-plates after 30 min and the number of miniature end-plate potentials which was maximum (562 ±... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Giant MEPPs; Myotoxicity; Neurotoxicity; Presynaptic action. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992005000100004 |
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| Borja-Oliveira,C. R.; Kassab,B. H.; Soares,A. M.; Toyama,M. H.; Giglio,J. R.; Marangoni,S.; Re,L.; Rodrigues-Simioni,L.. |
| Two presynaptic phospholipases A2 (PLA2), neuwieditoxin-I (NeuTX-I) and neuwieditoxin-II (NeuTX-II), were isolated from the venom of Bothrops neuwiedi pauloensis (BNP). The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column), followed by reverse phase HPLC (µBondapak C18 column). Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10µg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0±8.0% (n=3; p<0.05). NeuTX-I and NeuTX-II are probably... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chick biventer cervicis; Loose patch clamp; Nerve-muscle preparation; Neuromuscular junction; Neurotoxicity; PLA2 neurotoxin; Presynaptic action; Bothrops neuwiedi pauloensis; Neuwieditoxin-I; Neuwieditoxin-II. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992007000100008 |
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| Borja-Oliveira,C.R.; Durigon,A.M.; Vallin,A.C.C.; Toyama,M.H.; Souccar,C.; Marangoni,S.; Rodrigues-Simioni,L.. |
| The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada) venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 µg/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 µg/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 µM acetylcholine alone and cumulative concentrations of 1 µM to 10 mM were unaffected. At venom concentrations higher than 50 µg/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24ºC, the venom (50 µg/ml)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chick biventer cervicis; Myotoxicity; Neurotoxicity; Phospholipase A2; Presynaptic action. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000500009 |
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