Neutralization of the pharmacological effects of bothropstoxin-I from Bothrops jararacussu (jararacuçu) venom by crotoxin antiserum and heparin
| Autor: | Yoko Oshima-Franco, Gildo Bernardo Leite, Stephen Hyslop, Maria Alice da Cruz-Höfling, José Roberto Giglio, D.F. Cardoso, Léa Rodrigues-Simioni, Gustavo Henrique Rodrigues da Silva |
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| Rok vydání: | 2001 |
| Předmět: |
Male
Time Factors Injections Subcutaneous Myotoxin Antivenom Neuromuscular Junction Neuromuscular transmission Venom In Vitro Techniques Pharmacology Toxicology Mice Neutralization Tests Crotalid Venoms medicine Animals Bothrops Muscle Skeletal Antiserum Neuromuscular Blockade biology Antivenins Heparin Crotoxin biology.organism_classification Electric Stimulation Phrenic Nerve Immunoglobulin G Immunology Electrophoresis Polyacrylamide Gel Rabbits medicine.drug |
| Zdroj: | Toxicon. 39:1477-1485 |
| ISSN: | 0041-0101 |
| DOI: | 10.1016/s0041-0101(01)00107-6 |
| Popis: | Bothropstoxin-I (BthTX-I), the principal myotoxin of Bothrops jararacussu venom, is devoid of phospholipase A(2) (PLA(2)) activity but capable of blocking neuromuscular transmission in mouse nerve-muscle preparations. In this study, the ability of crotoxin antiserum and heparin in preventing the neurotoxic and myotoxic effects of BthTX-I was investigated. Phrenic nerve-diaphragm preparations (PND) stimulated indirectly with supramaximal stimuli (0.2 ms, 0.1 Hz) were incubated with BthTX-I (20 microg/ml) alone or with BthTX-I preincubated with antiserum or heparin for 30 min at 37 degrees C prior to testing. Control preparations were incubated with Tyrode solution, antiserum or heparin alone. BthTX-I (20 microg/ml) produced 50% neuromuscular blockade in the PND preparations in 31+/-4min, with complete blockade occurring in 120 min. The antiserum and heparin significantly prevented the neuromuscular blockade caused by BthTX-I (84 +/- 4% and 100% protection, respectively). Light microscopy examination of the muscles at the end of the 120 min incubation showed that BthTX-I damaged 48 +/- 6% of the fibers. Preincubating the toxin with antivenom significantly reduced the extent of this damage (only 15 +/- 4% of fibers affected, corresponding to 69% protection, P0.01) whereas heparin offered no protection (34 +/- 7% of fibers affected, not significantly different from that seen with toxin alone). These results show that the antivenom was more effective in neutralizing the myotoxic effects of BthTX-I than was heparin. |
| Databáze: | OpenAIRE |
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