Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations
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 m...
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| Format: | Article |
| Language: | English |
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SciELO
2005-03-01
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| Series: | Journal of Venomous Animals and Toxins including Tropical Diseases |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992005000100004 |
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| author | A. M. Durigon C. R. Borja-Oliveira C. A. Dal Belo Y. Oshima-Franco J. C. Cogo A. J. Lapa C. Souccar L. Rodrigues-Simioni |
| author_facet | A. M. Durigon C. R. Borja-Oliveira C. A. Dal Belo Y. Oshima-Franco J. C. Cogo A. J. Lapa C. Souccar L. Rodrigues-Simioni |
| author_sort | A. M. Durigon |
| collection | DOAJ |
| description | 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 ± 3%, p<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<0.01; n=4) in the end-plate region and from - 77.4 ± 1.4 to -44.6 ± 3.9 mV (24 fibers; p<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. |
| first_indexed | 2024-12-11T21:12:03Z |
| format | Article |
| id | doaj.art-3fe6636e949d40148986acf8b53b49a1 |
| institution | Directory Open Access Journal |
| issn | 1678-9199 |
| language | English |
| last_indexed | 2024-12-11T21:12:03Z |
| publishDate | 2005-03-01 |
| publisher | SciELO |
| record_format | Article |
| series | Journal of Venomous Animals and Toxins including Tropical Diseases |
| spelling | doaj.art-3fe6636e949d40148986acf8b53b49a12022-12-22T00:50:41ZengSciELOJournal of Venomous Animals and Toxins including Tropical Diseases1678-91992005-03-01111223310.1590/S1678-91992005000100004Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparationsA. M. DurigonC. R. Borja-OliveiraC. A. Dal BeloY. Oshima-FrancoJ. C. CogoA. J. LapaC. SouccarL. Rodrigues-SimioniThe 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 ± 3%, p<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<0.01; n=4) in the end-plate region and from - 77.4 ± 1.4 to -44.6 ± 3.9 mV (24 fibers; p<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.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992005000100004giant MEPPsmyotoxicityneurotoxicitypresynaptic action |
| spellingShingle | A. M. Durigon C. R. Borja-Oliveira C. A. Dal Belo Y. Oshima-Franco J. C. Cogo A. J. Lapa C. Souccar L. Rodrigues-Simioni Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations Journal of Venomous Animals and Toxins including Tropical Diseases giant MEPPs myotoxicity neurotoxicity presynaptic action |
| title | Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations |
| title_full | Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations |
| title_fullStr | Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations |
| title_full_unstemmed | Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations |
| title_short | Neuromuscular activity of Bothrops neuwiedi pauloensis snake venom in mouse nerve-muscle preparations |
| title_sort | neuromuscular activity of bothrops neuwiedi pauloensis snake venom in mouse nerve muscle preparations |
| topic | giant MEPPs myotoxicity neurotoxicity presynaptic action |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992005000100004 |
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