ABSTRACT
A phospholipase A2 has been isolated from Bothrops jararacussu venom from snakes that inhabit the northeast region of Argentina. The present study describes in vivo and in vitro biological activities of phospholipase A2 from B. jararacussu as well as isolation details of its. Venom was obtained by milking of adult snakes which were housing in wood reptile cages of varying dimensions in heated (20-30ºC) rooms. Snakes received a weekly diet of mice and water was available ad libitum for drinking and soaking. The enzyme was purified by gel filtration on a Sephadex G-75 column followed by ion exchange chromatography on a SP-Sephadex C25 column. The major peak belonging to proteins was retained in the cation exchanger and then eluted using a concentration gradient of KCl that exhibited phospholipase activity. This basic PLA2 consists of a single polypeptide chain with a molecular mass of 15.6 kDa. It had a high indirect hemolytic activity and produced a significant paw edema reaction in mice. The enzyme showed a low lethality (LD50 148.6 mg) when was administered i.p. but exhibited elevated myotoxic effects in vivo by increasing plasma CK activity of injected mice, corroborated results by the histological observations of samples of gastrocnemius muscle. Myonecrosis is the result of intense destruction of muscular fibers that involves local infiltration of inflammatory cells and leads to the highest peak of CK level just after 1 hour mice injection. Moreover, the isolated enzyme showed anticoagulant activity, evaluated on sheep platelet-poor plasma which recalcification time was prolonged after incubation with the isolated phospholipase A2. These findings showed that this phospholipase, isolated by only two simple chromatographic steps, possesses high edematogenic and myotoxic activities. However, despite the low lethal activity, this enzyme would contribute markedly to the pathophysiology of the bothropic envenomation.
ABSTRACT
Philodryas olfersii is found in South America, from Amazonas to Patagonia. It is important to characterize the venom of P. olfersii, who inhabits the North-East region of Argentina, since snake venoms are known to exhibit considerable variability in composition and biological activities. In this work, mice weighing 18-20 g (n = 4 for each experimental group) were used. For the edematogenic activity mice were injected s.c. in the right foot pad with 50 microl of solutions containing different amounts of venom, whereas the left foot pad was injected with 50 microl of PBS. Two hours after injection mice were killed by cervical dislocation and both feet were cut off and weighed individually. For the myotoxic activity mice were injected i.m. with 100 microl of solutions containing 40 microg of venom. Blood samples were extracted after 1, 3, 6, 8, 10, 12, 14, 16 and 24 h of venom injection to determinate serum CPK activity and mice were sacrificed at the same time intervals to obtain the inoculated gastrocnemius muscle. They were fixed with Bouin solution and stained with Hematoxylin-Eosin. Results showed that P. olfersii venom exhibits a high edematogenic activity (MED = 0.31 microg) and a moderate myotoxic activity. Myonecrosis reached its highest level after 12 h of venom injection as shown by plasmatic CPK levels (5,401 +/- 330 IU/l) and microscopic assay. It demonstrates the potential toxicity of the venom of P. olfersii, who inhabits the North-East region of Argentina. It also reinforces the original warning concerning the potential danger of bites by colubrids.
Subject(s)
Colubridae/physiology , Edema/chemically induced , Muscle, Skeletal/drug effects , Snake Venoms , Argentina , Colubridae/anatomy & histology , Creatine Kinase/blood , Edema/physiopathology , Salivary Glands/metabolism , Salivary Glands , Hemorrhage/chemically induced , Hemorrhage/physiopathology , Mice , Muscle, Skeletal/pathology , Muscle, Skeletal/physiopathology , Necrosis , Reaction Time/physiologyABSTRACT
Descreve-se a sintomatologIa e o tratamento de dois cäes picados por cascavel da America do Sul (Crotalus durissus terrificus) na Argentina. Sinais neurológicos foram evidentes poucos minutos após o acidente, incluindo anestesia local, ataxia do membro afetado e fascia neurotóxica. As enzimas aminotransferase da alanina, aminotransferase do aspartato, quinase da creatinina, desidrogenase de lactato e o cálcio foram determinados para analisar dano muscular. Falha rEnal näo foi observada, mas algumas alteraçöes foram detectadas na urina, incluindo densidade baixa, sedimento com grumos granulares e células pequenas redondas. Biópsias de músculo foram obtidas de ambas as pernas para histopatología, revelando edema e fibras necróticas isoladas. Ambos os cäes receberam tratamento quatro horas após o acidente, pela via intravenosa. A antitoxina foi administrada diluída em 250ml de soluçäo Ringer lactato na dose capaz de neutralizar 8mg de toxina. Dexametasona foi aplicada antes de administrar a antitoxina. A evoluçäo clínica foi boa e ambos os pacientes estavam com boa saúde no segundo dia após a acidente
Subject(s)
Animals , Male , Female , Accidents , Crotalus , DogsABSTRACT
Se realizó el estudio de las actividades hemorrágica, edematizante, proteolítica y mionecrótica inducida por veneno de viboreznos de Bothrops alternatus de Argentina. Los venenos estudiados poseen las actividades mensionadas, mostrando marcadas diferencias respecto al veneno de ejemplares adultos. Cuadriplica la capacidad hemorrágica, supera en más de diez veces la edematizante. La actividad proteolítica es la que menor diferencia posee. El análisis histológico mostró intensa hemorragia y miólisis de fibras musculares a los 60 minutos de exposición al veneno. La mionecrosis y el exudado inflamatório fueron más altos en las siguientes horas. La hemorragia disminuyó de 24 horas y la regeneración de las fibras musculares se inició en la primer semana con formación de tejido de granulación. A la cuarta semana se observaban áreas de regeneración de fibras musculares y aún se observada tejido de granulación. Se concluye que la injuria producida en los accidentes por viboreznos de Cothrops alternatus es más intensas que la inducida por ejemplares adultos de la misma especie.
Subject(s)
Animals , Mice , Bothrops , Crotalid Venoms/toxicity , Edema/chemically induced , Hemorrhage/chemically induced , Muscle Fibers, Skeletal/pathology , Muscle, Skeletal/pathology , Peptide Hydrolases/metabolism , Argentina , Muscle Fibers, Skeletal/physiology , Necrosis , RegenerationABSTRACT
Se estudiaron las actividades hemorrágica, edematizante, proteolítica, hemolítica indirecta (in vitro) y por microscopía óptica la mionecrosis y regeneración de fibras musculares inducidas por veneno de Bothrops moojeni de Argentina. El veneno demostró poseer las actividades mensionadas. La actividad mionecrótica fue intensa a partir de los 60 minutos de exposición incrementando su intensidad a las 3 horas con predominio de lesiones de fibras musculares de tipo miolótico, respecto a necrosis coagulativa. En los cortes histológicos, la hemorragia fue mínima al igual que el edema, mientras que a las 3 horas se observó infiltrado inflamatorio polimorfonuclear con predominio de neutrófilos y a partir de las 48 horas se sumaron los macrófagos. Al tercer día se observaron fibroblastos, los que se incrementaron paulatinamente; a los 7 días se observó regeneración de algunas fibras musculares que presentaban estriaciones, a partir de la curta semana, éstas alternaban con áreas calcificadas. La recuperación de las lesiones fue parcial, con fibras musculares de menor diámetro que las normales, alterando con áreas de calcificación y otras de fibrosis. Las lesiones causadas por el veneno de Bothrops moojeni son intensas y por la recuperación parcial de las mismas, puede generar pérdida importante de tejidos, con secuelas funcionales.
Subject(s)
Animals , Rats , Bothrops , Crotalid Venoms/toxicity , Edema/chemically induced , Hemolysis , Hemorrhage/chemically induced , Muscle Fibers, Skeletal/pathology , Muscle, Skeletal/pathology , Peptide Hydrolases/metabolism , Phospholipases A/metabolism , Argentina , Muscle Fibers, Skeletal/physiology , Necrosis , RegenerationABSTRACT
Se estudiaron las actividades edematizante y mionecrótica inducidas por veneno de Bothrops jararaca de Argentina. Para la actividad edematizante se inocularon ratones con distintas dosis de veneno diluído en 0.05 ml de solución fisiológica. La dosis de 0.86 mug/20g ratón provocó un edema del 30 por ciento respecto al miembro opuesto en 1 hora. La evaluación de los efectos mionecróticos se realizó en ratones inoculados en el músculo gastroenemio con 70 mug de veneno em 0.1 ml de solución fisiológica, los que se sacrificaron en distinos tiempos de exprosición. Del área de inoculación se obtuvo material para procesamiento histopatológico. Los animales sacrificados a los 30 y 60 minutos revelaron edema y mionecrosis. Aquellos que se sacrificaron a las tres horas después de la inoculación, edemas de edema y hemorragia, presentaron necrosis e infiltrado inflamatorio.