FINAL ACCEPTED VERSION JN-001555-2003.R2 Promiscuous and Reversible Blocker of Presynaptic Calcium Channels in Frog and Crayfish Neuromuscular Junctions from Phoneutria nigriventer Spider Venom
نویسندگان
چکیده
1. Dept. Physiology, University of Toronto, 1 King’s College Circle, Toronto, ON, Canada M5S 1A8. 2. Instituto Butantan, Lab. of Pharmacology, Biochemistry and Immunochemistry, respectively, São Paulo, SP, Brazil. 3. Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON, Canada M5G 1X5. 4. Current address: Department of Biological Science, Barnard College, New York, NY, 10027, USA.
منابع مشابه
Promiscuous and reversible blocker of presynaptic calcium channels in frog and crayfish neuromuscular junctions from Phoneutria nigriventer spider venom.
Peptide channel blockers found in venoms of many predators are useful pharmacological tools and potential therapeutic agents. The venom of the Brazilian spider Phoneutria nigriventer contains a fraction, omega-phonetoxin-IIA (omega-Ptx-IIA, 8360 MW), which blocks Ca2+ channels. At frog neuromuscular junctions (NMJ) bathed in normal Ca2+ (1.8 mM) saline, omega-Ptx IIA did not affect spontaneous ...
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The present experiments investigated the effect of some of the toxic components present in the venom of the spider Phoneutria nigriventer on the release of neurotransmitter. The toxic fraction, Phoneutria nigriventer toxin-3 (PhTx3), abolished Ca2+-dependent glutamate release, but did not alter Ca2+-independent secretion of glutamate when rat brain cortical synaptosomes were depolarized with 33...
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The changes induced in the mean arterial blood pressure of anaesthetised rats following the administration of armed spider (Phoneutria nigriventer) venom have been investigated. The intravenous injection of Phoneutria nigriventer venom (0.1 mg/kg) evoked a brief and reversible decrease in the mean arterial blood pressure whereas a higher dose of venom (0.3 mg/kg) caused a biphasic response char...
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