Data/hora: 16/06/2024 09:34:11

Provedor de dados: | Journal of Venomous Animals and Toxins Including Tropical Diseases
País: | Brazil
Título: | Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations
Autores: | 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.
Data: | 2005-03-01
Ano: | 2005
Palavras-chave: | Giant MEPPs; Myotoxicity; Neurotoxicity; Presynaptic action.
Resumo: | 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&lt;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&lt;0.05; n=3) after 120 min. Venom (20 mug/ml) increased (25 ± 2%, p&lt; 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 ± 3%, p&lt;0.05) after 120 min. During the same period, the resting membrane potential decreased from - 81 ± 1.4 mV to - 41.3 ± 3.6 mV 24 fibers; p&lt;0.01; n=4) in the end-plate region and from - 77.4 ± 1.4 to -44.6 ± 3.9 mV (24 fibers; p&lt;0.01; n=4) in regions distant from the end-plate. These results indicate that B. n. pauloensis venom acts primarily at presynaptic sites. They also suggest that enzymatic activity may be involved in this pharmacological action.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992005000100004
Editor: | Centro de Estudos de Venenos e Animais Peçonhentos
Relação: | 10.1590/S1678-91992005000100004
Formato: | text/html
Fonte: | Journal of Venomous Animals and Toxins including Tropical Diseases  v.11 n.1 2005
Fonte: | info:eu-repo/semantics/openAccess