RESUMO

Systemic alterations induced by a Bothrops alternatus hemorrhagin, named baltergin, a 55kDa fibrinogenolytic metalloproteinase isolated from venom of north-eastern Argentina specimens, were studied in mice. It caused macroscopic hemorrhagic spots in lungs which was injected intravenously with a minimum pulmonary hemorrhagic dose of 10microg. Histological observations of lungs showed mainly hemorrhagic areas, evidenced by the presence of erythrocytes in the alveolar spaces, congestion and increase of thickness of alveolar septum due to polymorphonuclear infiltrate and mononuclear cells. Neither macroscopic hemorrhage in other organs nor histological alterations in heart and cerebrum/cerebellum were observed at doses assayed. However, kidney and liver were mildly affected. Kidney examination revealed congestion, subcapsular hemorrhage with local capsule detachment, inflammatory infiltrate and degeneration of tubular cells. Congestion of blood vessels and hydropic degeneration of hepatocytes were observed in liver. Besides, baltergin was able to further hydrolyze type IV collagen. Although the enzyme showed to be less lethal than whole venom, it induced severe pulmonary bleeding and affected kinder and liver in minor grade. In conclusion, baltergin is able to alter the integrity of capillary vessels and simultaneously, to interfere on the hemostatic system. Thus, this metalloproteinase contribute markedly to systemic alterations characteristic of B. alternatus envenomations.

Assuntos

RESUMO

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.(AU)

RESUMO

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.

RESUMO

Due to variability of venom components from the same species of snakes that inhabit different regions, particular properties of the venom of Crotalus durissus terrificus that inhabits the North-East of Argentina were studied. Gyroxin, a thrombin-like enzyme, was isolated from this venom by gel filtration and affinity chromatography, it was found to be homogeneous according to SDS-PAGE, with a molecular weight of 33 kDa. [quot ]Gyroxin syndrome[quot ] in mice was tested and it showed changes in the animal behavior, confirming that the isolated thrombin-like enzyme is gyroxin. Effects of this enzyme and the crude venom on mice plasmatic fibrinogen levels were determined. The mice plasma fibrinogen decreased rapidly until incoagulability during the first hour after thrombin-like enzyme injection, then reaching its normal level 10 hours after injection; whereas crude venom resulted in a 60% decrease of the mice plasma fibrinogen, reaching its normal level after the same period of time. After 1 hour of gyroxin inoculation, intravascular coagulation was observed in histological cuttings of lung, cardiac muscle and liver. The isolated enzyme showed strong hydrolyzing activity on fibrinogen and fibrin in vitro, whereas the crude venom exhibited weak hydrolyzing activity on both substrates. It is probable that this very low activity is due to the low percentage of the enzyme in the crude venom. Decreasing of plasmatic fibrinogen levels may be due to either the coagulant or hydrolyzing actions of the enzyme.

Teniendo en cuenta la variabilidadde los componentes del veneno de serpientes de una misma especie que habitan regiones diferentes, se decidióestudiar las propiedades particulares del veneno de Crotalus durissus terrificus que habita el nordeste de Argentina, Giroxina, una enzima con actividad trombínica, fue aislada del veneno por cromatografía de filtración por gel y de afinidad; se comprobó su homogeneidad y se determinó su peso molecular, 33 kDa, por SDSPAGE. Se ensayó el síndrome giroxina en ratones, los que mostraron cambios en el comportamiento, confirmandoque la enzima tipo trombina aislada es giroxina. Se evaluó la acción de esta enzima sobre los niveles de fibrinógeno plasmático en ratones, comparándola con la del veneno crudo. Se comprobó que la enzima provoca una disminución de los niveles plasmáticos de fibrinógeno hasta la incoagulabilidad, durante la primer hora de inoculación, mientras que el veneno entero produjo una reducción del nivel plasmático en un 60%; sin embargo, en ambos casos, se evidenció una rápida reposición de fibrinógeno plasmático, alcanzando sus valores normales en un plazo de 10 horas. Se observó coagulación intravascular con la administración de giroxina una hora después de la inoculación, evidenciados en estudios histológicos de tejido pulmonar, cardíaco y hepático. En ensayos realizados in vitro, la enzima aislada mostró capacidad de degradar fibrinógeno como así también coágulos de fibrina, mientras que el veneno exhibió débil actividad hidrolítica sobre ambos sustratos. Es probable que esta baja actividad sea debida a la baja concentración de la enzima en el veneno. La disminución de los niveles de fibrinógeno plasmático observado en ratones se debería a la acción coagulante de la enzima, sin embargo no se descarta que también contribuya a este proceso una acción hidrolítica sobrefibrinógeno y fibrina por parte de la enzima.

Assuntos

RESUMO

Due to variability of venom components from the same species of snakes that inhabit different regions, particular properties of the venom of Crotalus durissus terrificus that inhabits the North-East of Argentina were studied. Gyroxin, a thrombin-like enzyme, was isolated from this venom by gel filtration and affinity chromatography, it was found to be homogeneous according to SDS-PAGE, with a molecular weight of 33 kDa. [quot ]Gyroxin syndrome[quot ] in mice was tested and it showed changes in the animal behavior, confirming that the isolated thrombin-like enzyme is gyroxin. Effects of this enzyme and the crude venom on mice plasmatic fibrinogen levels were determined. The mice plasma fibrinogen decreased rapidly until incoagulability during the first hour after thrombin-like enzyme injection, then reaching its normal level 10 hours after injection; whereas crude venom resulted in a 60% decrease of the mice plasma fibrinogen, reaching its normal level after the same period of time. After 1 hour of gyroxin inoculation, intravascular coagulation was observed in histological cuttings of lung, cardiac muscle and liver. The isolated enzyme showed strong hydrolyzing activity on fibrinogen and fibrin in vitro, whereas the crude venom exhibited weak hydrolyzing activity on both substrates. It is probable that this very low activity is due to the low percentage of the enzyme in the crude venom. Decreasing of plasmatic fibrinogen levels may be due to either the coagulant or hydrolyzing actions of the enzyme.(AU)

Teniendo en cuenta la variabilidadde los componentes del veneno de serpientes de una misma especie que habitan regiones diferentes, se decidióestudiar las propiedades particulares del veneno de Crotalus durissus terrificus que habita el nordeste de Argentina, Giroxina, una enzima con actividad trombínica, fue aislada del veneno por cromatografía de filtración por gel y de afinidad; se comprobó su homogeneidad y se determinó su peso molecular, 33 kDa, por SDSPAGE. Se ensayó el síndrome giroxina en ratones, los que mostraron cambios en el comportamiento, confirmandoque la enzima tipo trombina aislada es giroxina. Se evaluó la acción de esta enzima sobre los niveles de fibrinógeno plasmático en ratones, comparándola con la del veneno crudo. Se comprobó que la enzima provoca una disminución de los niveles plasmáticos de fibrinógeno hasta la incoagulabilidad, durante la primer hora de inoculación, mientras que el veneno entero produjo una reducción del nivel plasmático en un 60%; sin embargo, en ambos casos, se evidenció una rápida reposición de fibrinógeno plasmático, alcanzando sus valores normales en un plazo de 10 horas. Se observó coagulación intravascular con la administración de giroxina una hora después de la inoculación, evidenciados en estudios histológicos de tejido pulmonar, cardíaco y hepático. En ensayos realizados in vitro, la enzima aislada mostró capacidad de degradar fibrinógeno como así también coágulos de fibrina, mientras que el veneno exhibió débil actividad hidrolítica sobre ambos sustratos. Es probable que esta baja actividad sea debida a la baja concentración de la enzima en el veneno. La disminución de los niveles de fibrinógeno plasmático observado en ratones se debería a la acción coagulante de la enzima, sin embargo no se descarta que también contribuya a este proceso una acción hidrolítica sobrefibrinógeno y fibrina por parte de la enzima. (AU)

Assuntos

RESUMO

A study of hemorrhagic, edema-forming, proteolytic and myonecrotic activities induced by newborn Bothrops alternatus snake venoms from Argentina was performed. The analyzed venom had these activities with markedly differences when compared with the venom of adult specimens. Hemorrhagic activity was four times higher, while edema forming activity was ten times or more. But proteolytic activity was similar in both groups. Hystological analysis showed intense hemorrhage and muscular fiber myolisis after 60 minutes of venom injection. Myonecrosis and inflammatory exudate were higher in the following hours. Hemorrhage decreased after 24 hours and muscular fiber regeneration started after the first week with granulation tissue formation. On the fourth week regenerating muscular fiber areas and granulation tissue were still observed. As a conclusion, we can assume that the injury induced in the snake accident by newborn Bothrops alternatus snakes would be more intense than those induced by the adult ones.

Assuntos

RESUMO

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.

Assuntos

RESUMO

A study of hemorrhagic, edema-forming, proteolytic and myonecrotic activities induced by newborn Bothrops alternatus snake venoms from Argentina was performed. The analyzed venom had these activities with markedly differences when compared with the venom of adult specimens. Hemorrhagic activity was four times higher, while edema forming activity was ten times or more. But proteolytic activity was similar in both groups. Hystological analysis showed intense hemorrhage and muscular fiber myolisis after 60 minutes of venom injection. Myonecrosis and inflammatory exudate were higher in the following hours. Hemorrhage decreased after 24 hours and muscular fiber regeneration started after the first week with granulation tissue formation. On the fourth week regenerating muscular fiber areas and granulation tissue were still observed. As a conclusion, we can assume that the injury induced in the snake accident by newborn Bothrops alternatus snakes would be more intense than those induced by the adult ones.

RESUMO

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. (AU)

Assuntos