| Influence of temperature upon effects of crotoxin and gamma-irradiated crotoxin at rat neuromuscular transmission. | |
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MedLine Citation:
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PMID: 10713471 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The influence of temperature upon the effects of crotoxin (CTX), from Crotalus durissus terrificus venom, and gamma-irradiated (60Co, 2000 Gy) crotoxin (iCTX) was studied in rat neuromuscular transmission 'in vitro'. Indirect twitches were evoked in the phrenic-diaphragm preparation by supramaximal strength pulses with a duration of 0.5 ms and frequency of 0.5 Hz. The phospholipase A(2) (PLA(2)) enzymatic activity of CTX and iCTX was assayed against phosphadityl choline in Triton X-100. At 27 degrees C, CTX (14 microg/ml) did not affect the amplitude of indirectly evoked twitches. However, at 37 degrees C, CTX induced a time-dependent blockade of the neuromuscular transmission that started at 90 min and was completed within 240 min. iCTX (14 microg/ml) was inneffective on the neuromuscular transmission either at 27 or 37 degrees C. The PLA(2) enzymatic activity of CTX at 37 degrees C was 84 and that at 27 degrees C was 27 micromol fatty acid released/min/mg protein, and that of the iCTX at 37 degrees C was 39 micromol fatty acid released/min/mg protein. Thus, it was concluded that the mechanism of detoxification of CTX by gamma radiation at the neuromuscular level relies on the loss of its PLA(2) enzymatic activity. |
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Authors:
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M Gallacci; N Nascimento; J R Rogero; V S Vassilieff |
Publication Detail:
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Type: In Vitro; Journal Article |
Journal Detail:
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Title: Toxicology letters Volume: 114 ISSN: 0378-4274 ISO Abbreviation: Toxicol. Lett. Publication Date: 2000 Apr |
Date Detail:
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Created Date: 2000-05-01 Completed Date: 2000-05-01 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 7709027 Medline TA: Toxicol Lett Country: NETHERLANDS |
Other Details:
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Languages: eng Pagination: 77-80 Citation Subset: IM |
Affiliation:
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Departamento de Farmacologia, Instituto de Biociências-UNESP, Universidade Estadual Paulista, Rubião Júnior, Botucatu, São Paulo, Brazil. gallacci@ibb.unesp.br |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Crotoxin / radiation effects*, toxicity* Diaphragm / drug effects*, innervation Enzyme Activation / radiation effects Gamma Rays Male Muscle Contraction / drug effects, physiology Neuromuscular Junction / drug effects* Phospholipases A / metabolism, radiation effects Phrenic Nerve / drug effects, physiology Rats Synaptic Transmission / drug effects* Temperature* |
| Chemical | |
Reg. No./Substance:
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9007-40-3/Crotoxin; EC 3.1.1.-/Phospholipases A |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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