The effects of green pit viper (Trimeresurus albolabris and Trimeresurus macrops) venom on the fibrinolytic system in human (original) (raw)
Related papers
Toxicon, 1982
Crude venom from B. gabonica contained weak fibrinogen clotting activity but no visible fibrinolytic activity, whereas venoms from A. p. piscivorus and A. c. contortrix exhibited fibrinolytic activity (by fibrin plate assay) but no thrombin-like activity. These snake venoms were fractionated on Sephadex G-100 with the following results. Thrombin-like activity in B. gabonica venom was eluted in a single protein peak with a molecular weight of 40,000. Agkistrodon p. piscivorus venom contained a single peak of fibrinolytic activity with a molecular weight of 34,000. Interestingly, venom from A. c. contortrix, which showed no thrombin-like activity in crude venom, contained both thrombin-like and fibrinolytic activities in fractions with molecular weights of 73,000 and 25,000 respectively. No plasminogen activation activity was observed in any of the crude venoms or venom fractions eluted from G-100. In view of the possible clinical potential of these enzymes as defibrinogenating or thrombolytic agents, it will be of great interest to further purify and characterize them.
Japanese Journal of Medical Science and Biology, 1984
The effects of Russell's viper venom on blood coagulation, platelets and the fibrinolytic enzyme system were studied in rabbits after injecting repeated doses of 0.05 MLD of the venom. Thrombocytopenia was the earliest change to appear. It was followed by rise in serum fibrinogen degradation products and prolongation of prothrombin time, activated partial thromboplastin time and thrombin time indicating a progressive consumption coagulopathy and activation of fibrinolytis. Red blood cell morphology was unchanged during the first three weeks; whereas the fragmentation appeared after the fourth week and it increased in severity with further envenomations, i.e. when chronic DIC was established.
Fibrinogenolysis in Venom-Induced Consumption Coagulopathy after Viperidae Snakebites: A Pilot Study
Toxins
Envenomations that are caused by Viperidae snakebites are mostly accompanied by venom-induced consumption coagulopathy (VICC) with defibrination. The clinical course of VICC is well described; however, reports about its detailed effects in the hemocoagulation systems of patients are sparse. In this pilot study, we prospectively analyzed the changes in plasma fibrinogen that were caused by the envenomation of six patients by five non-European Viperidae snakes. Western blot analysis was employed and fibrinogen fragments were visualized with the use of specific anti-human fibrinogen antibodies. All of the studied subjects experienced hypo- or afibrinogenemia. The western blot analysis demonstrated fibrinogenolysis of the fibrinogen chains in all of the cases. Fibrinogenolysis was considered to be a predominant cause of defibrination in Crotalus, Echis, and Macrovipera envenomation; while, in the cases of VICC that were caused by Atheris and Calloselasma envenomation, the splitting of t...
Comparative Biochemistry and Physiology C-toxicology & Pharmacology, 2008
Bothrops colombiensis venom from two similar geographical locations were tested for their hemostatic functions and characterized by gelfiltration chromatography and SDS-PAGE electrophoresis. The snakes were from Caucagua and El Guapo towns of the Venezuelan state of Miranda. Fibrino(geno)lytic, procoagulant, hemorrhagic, lethal activities, gel-filtration chromatography and SDS-PAGE profiles were analyzed and compared for both venoms. The highest hemorrhagic activity of 5.3 μg was seen in El Guapo venom while Caucagua venom had the lowest LD 50 of 5.8 mg/kg. Both venoms presented similar thrombin-like activity. El Guapo showed a factor Xa-like activity two times higher than Caucagua. Differences were observed in kallikrein-like and t-PA activities, being highest in El Guapo. Caucagua venom showed the maximum fibrin lysis. Both crude venom runs on Sephadex G-100 chromatography gave fraction SII with the high fibrinolytic activity. Proteases presented in SII fractions and eluted from Benzamidine-Sepharose (not bound to the column) provoked a fast degradation of fibrinogen α chains and a slower degradation of β chains, which could possibly be due to a higher content of α fibrinogenases in these venoms. The fibrinogenolytic activity was decreased by metalloprotease inhibitors. The results suggested that metalloproteases in SII fractions were responsible for the fibrinolytic activity. The analysis of samples for fibrinzymography of SII fractions showed an active band with a molecular mass of approximately 30 kDa. These results reiterate the importance of using pools of venoms for antivenom immunization, to facilitate the neutralization of the maximum potential number of toxins.
Toxicon, 2010
Venom-induced consumption coagulopathy occurs in snake envenoming worldwide but the interaction between procoagulant snake venoms and human coagulation remains poorly understood. We aimed to evaluate an assay using endogenous thrombin potential (ETP) to investigate the procoagulant properties of a range of Australian whole venoms in human plasma and compared this to traditional clotting and prothrombinase activity studies. We developed a novel modification of ETP using procoagulant snake venoms to trigger thrombin production. This was used to characterise the relative potency, calcium and clotting factor requirements of five important Australian snake venoms and efficacy of commercial antivenom, and compared this to prothrombinase activity and clotting assays. All five venoms initiated thrombin generation in the absence and presence of calcium. Pseudonaja textilis (Brown snake; p < 0.0001), Hoplocephalus stephensii (Stephen's-banded snake; p < 0.0001) and Notechis scutatus (tiger snake; p ¼ 0.0073) all had statistically significant increases in ETP with calcium. Venom potency varied between assays, with ETP ranging from least potent with Oxyuranus scutellatus (Taipan) venom to intermediate with N. scutatus and H. stephensii venoms to most potent with P. textilis and Tropidechis carinatus (Rough-scale snake) venoms. ETPs for N. scutatus, T. carinatus and H. stephensii venoms were severely reduced with factor V deficient plasma. Antivenom neutralized the thrombin generating capacity but not prothrombin substrate cleaving ability of the venoms. Contrary to previous studies using clotting tests and factor Xa substrates, these venoms differ in calcium requirement. ETP is a useful assay to investigate mechanisms of other procoagulant venoms and is a robust method of assessing antivenom efficacy.
Determination of the fibrinogenolytic activity of Montivipera raddei (Raddeʼs mountain viper) venom
Archives of Biological Sciences
Snake venom fibrinogenolytic enzymes have diagnostic and therapeutic value and are important for snakebite pathology. In the present study, the fibrinogenolytic activity of Montivipera raddei venom was investigated. Crude venom was incubated with human fibrinogen for different times at 37?C. An inhibition study was carried out using different protease inhibitors. The fibrinogenolytic activity was assessed by SDS-PAGE and fibrinogen zymography. An HPLC-based method was used to obtain confirmatory data. Montivipera raddei venom predominantly cleaved the A? chain of fibrinogen in a time-dependent manner. A very slight decrease in band intensity of the B? chain was observable after a longer incubation time. Cleavage of fibrinogen was confirmed by HPLC. Zymography revealed that the venom contained 50 and 75 kDa fibrinogenolytic enzymes. Ethylenediaminetetraacetic acid (EDTA) and 1,10-phenanthroline inhibited the overall fibrinogenolytic activity, while phenylmethylsulfonyl fluoride (PMSF...
Medicina, 2004
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. "Gyroxin syndrome" 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. Af...
Thrombosis Research, 2007
Venom constitution within the same snake species can present considerable geographical variations. Bothrops atrox venoms were obtained from adult snakes captured at different geographical locations: Parguasa (Bolívar state); Puerto Ayacucho 1, Serranía del Cuao and Puerto Ayacucho 2 (Amazon state). The coagulant and fibrinolytic activities of these venoms were compared. Amidolytic activity of crude snake venom was measured by a micromethod designed in our laboratory. Coagulant activity on plasma and fibrinogen due to thrombin-like activity in venoms was also determined. Crude snake venom fibrinolytic activity by the fibrin plate method was assayed. Chromatographic studies were developed on Protein-Pack 300 column. Polyacrylamide gel electrophoresis was carried out under reduced conditions. After SDS-PAGE of samples, the fibrin-zymography was tested on agarose-fibrin plates.