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Local tissue damage induced by crotaline snake venoms includes edema, myonecrosis, hemorrhage, and an inflammatory response associated with a prominent cellular infiltrate. The role of neutrophils in the local tissue damage induced by Bothrops asper snake venom and by myotoxin I, a phospholipase A2 isolated from this venom, was investigated. Male Swiss mice(More)
A new muscle damaging toxin, myotoxin II, was purified from the venom of Bothrops asper by ion-exchange chromatography on CM-Sephadex C-25. The toxin is a dimeric, basic protein with a monomer mol.wt of 13,341, according to the amino acid composition, and 16,000 on the basis of SDS-polyacrylamide gel electrophoretic mobility. It has a high number of(More)
The ability of Lys49 and Asp49 phospholipases A(2) (PLA(2)), from Bothrops asper snake venom, to cause hyperalgesia was investigated in rats, using the paw pressure test. Intraplantar injection of both toxins (5-20 micro g/paw) caused hyperalgesia, which peaked 1h after injections. Incubation of both proteins with heparin, prior to their injection,(More)
In the isolated mouse diaphragm preparation, Micrurus nigrocinctus venom produced a dose-dependent contracture and blockade of the contractile response to direct and indirect electrical stimulation of the muscle. This effect could not be completely reversed by repeated washing of the preparation nor by the addition of neostigmine or 3, 4-diaminopyridine.(More)
The hemorrhagic activity characteristic of viperid snake envenomations is due to the action of venom metalloproteinases (SVMPs) on the capillary vessel basement membrane (BM). This study compared the action of two SVMPs on BM in vitro (degradation of Matrigel) and in vivo (immunohistochemical assessment of BM markers in mouse gastrocnemius muscle). SVMPs(More)
Venoms from eight Bothrops spp. were fractionated by ion-exchange chromatography on CM-Sepharose at pH 8.0 for the purification of myotoxins. Chromatographic profiles showed differences regarding myotoxic components among these venoms. B. alternatus, B. atrox and B. jararaca venoms did not show the major basic myotoxic fractions identified in the other(More)
The coagulant, defibrinating, fibrino lytic and fibrinogenolytic activities of venoms from ten species of Costa Rican crotaline snakes were studied, together with the neutralization of these effects by a polyvalent antivenom. The venoms of Bothrops asper, B. schlegelii, B. nummifer, B. godmani, Lachesis muta and Crotalus durissus induced a coagulant effect(More)
Zinc-dependent metalloproteinases are responsible for the hemorrhagic activity characteristic of viperid snake venoms. Snake venom metalloproteinases (SVMPs) are classified in various groups (P-I-IV), according to their domain composition. P-III SVMPs, comprising metalloproteinase, disintegrin-like and cysteine-rich domains, exert more potent hemorrhagic(More)
The polyvalent antivenom produced at the Instituto Clodomiro Picado, Costa Rica, was tested for its capacity to neutralize proteolytic and hemorrhagic activities of ten Costa Rican crotaline venoms. In experiments with preincubation of venom and antivenom, the latter efficiently neutralized proteolytic activities of nine venoms, with ED50 ranging from 50 to(More)
E nvenoming resulting from snake bites is an important public health hazard in many regions, particularly in tropical and subtropical countries [1–3]. Although antivenoms are being produced by various laboratories in every continent, the burden of snake bite envenoming— causing both morbidity and mortality—still has a great impact on the population and on(More)