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Methods in Molecular Biology (Clifton,... 2013The reptilase time is a functional plasma clotting assay, which is based on the enzymatic activity of batroxobin. By specifically cleaving fibrinogen A from fibrinogen,...
The reptilase time is a functional plasma clotting assay, which is based on the enzymatic activity of batroxobin. By specifically cleaving fibrinogen A from fibrinogen, batroxobin leads to the formation of a stable fibrin clot. The time, starting from the addition of batroxobin to the plasma sample, until clot formation is the reptilase time and is given in seconds. Clot formation can be detected manually or on automated coagulation systems. Reference values for healthy adults are 18-22 s. Healthy newborns may have a slightly prolonged reptilase time of up to 24 s. In addition to other coagulation assays, the reptilase time is usually performed to confirm or to exclude the suspicion of dysfibrinogenemias. The reptilase time is independent of thrombin generation disturbances or disturbances in the action of thrombin on fibrinogen. Therefore, it can be used to confirm heparin contamination or to obtain similar information as with the thrombin clotting time in heparinized and hemophiliac patients.
Topics: Afibrinogenemia; Batroxobin; Blood Coagulation; Hemostatics; Humans; Thrombin Time
PubMed: 23546720
DOI: 10.1007/978-1-62703-339-8_20 -
Cellular and Molecular Neurobiology Apr 2011Multiple sclerosis (MS) was characterized with widespread demyelination and axonal loss of central nervous system (CNS). Fibrinogen (fibrin) deposition was considered as...
Multiple sclerosis (MS) was characterized with widespread demyelination and axonal loss of central nervous system (CNS). Fibrinogen (fibrin) deposition was considered as one of the pathogenesis of MS. Therefore, we explored the effects of fibrinogen depleting agent batroxobin in experimental autoimmune encephalomyelitis (EAE) mice model. Our study showed that prevention and suppression with batroxobin significantly ameliorated clinical severity of EAE, reduced inflammatory cells infiltration, and demyelination, and suppressed the activation of astrocytes and macrophages comprising the CD11b(+) population. Batroxobin treatment leads to reduced expression of p-Akt and increased expression of MBP as compared to control. In addition, batroxobin treatment partly reversed the dendric-like formation of macrophages irritated by fibrinogen in vitro. The reduced severity of EAE mice treated with batroxobin suggests that strategy targeting fibrin as a potential therapy for EAE may be beneficial for the treatment of MS patients.
Topics: Animals; Batroxobin; Cell Line; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Female; Fibrinogen; Humans; Lipopolysaccharides; Macrophages; Mice; Mice, Inbred C57BL; Spinal Cord
PubMed: 21165693
DOI: 10.1007/s10571-010-9637-2 -
Acta Oto-laryngologica Nov 1992Cochlear blood flow is considered to be closely related to cochlear function. Among several etiologic factors implicated in inner ear diseases, disturbance of local...
Cochlear blood flow is considered to be closely related to cochlear function. Among several etiologic factors implicated in inner ear diseases, disturbance of local blood flow is held to be one of the most important. With this in view, various pharmaceuticals are currently being used to increase local blood flow in patients with inner ear diseases. In the control of blood flow there are three major factors; systemic blood pressure (perfusion pressure), vascular tone, and blood viscosity. Batroxobin (BX) was developed to increase local blood flow by lowering blood viscosity through defibrinogenation; it is used in the treatment of thrombosis and occasionally for the treatment of sudden deafness. In the present study, we observed the effect of BX on cochlear blood flow in guinea pigs, using a laser Doppler flowmeter, and measured the blood fibrinogen concentration after BX infusion. There was an obvious increase in cochlear blood flow during the observation period of 3 h after 10 BU/kg were infused, and a slight increase when 2 BU/kg were infused. Blood fibrinogen levels decreased dramatically by 30 min after BX infusion (10 BU/kg), and the extremely low level attained was maintained throughout the 3-h observation period. Hemorrhage from the surgically opened ear was noted in 2 animals during the experiment and rectal bleeding in one.
Topics: Animals; Batroxobin; Blood Pressure; Cochlea; Fibrinogen; Fibrinolysis; Guinea Pigs; Laser-Doppler Flowmetry; Microcirculation; Regional Blood Flow
PubMed: 1481670
DOI: 10.3109/00016489209137500 -
Echocardiography (Mount Kisco, N.Y.) Nov 2014Our objective was to determine whether continuous transcranial Doppler (TCD) monitoring could safely enhance the efficacy of batroxobin, a thrombin-like enzyme extracted... (Comparative Study)
Comparative Study Randomized Controlled Trial
Our objective was to determine whether continuous transcranial Doppler (TCD) monitoring could safely enhance the efficacy of batroxobin, a thrombin-like enzyme extracted from Bothrops atrox moojeni venom, in the treatment for acute cerebral stroke beyond the thrombolytic time window. Ninety patients suffering an acute cerebral stroke were recruited into the study within 12 hours after the onset of symptoms. Patients were randomized to receive batroxobin with (target group) or without 1 hour of continuous TCD monitoring (control group). Clinical evaluation of stroke was based on the National Institutes of Health Stroke Scale (NIHSS) score, Barthel index (BI), Thrombolysis in Brain Ischemia score (TIBI), the incidence of advancing stroke, and the recurrence of cerebral infarction. The patients receiving continuous TCD monitoring showed significant improvement in NIHSS score at 57 days post treatment compared with the control. Similarly, patients receiving continuous TCD monitoring also showed significant improvement in BI at 3 months compared with the controls. Consistently, both the incidence of advancing stroke after 1 week and the incidence of stroke recurrence after 3 months were significantly lower in TCD monitored group than control group. Moreover, the safety of the employment of TCD monitoring in the treatment of these patients was confirmed as there was no significant difference of the incidence of intracranial hemorrhage at 1 week after the treatment between the target and control groups. Taken together, our study showed that batroxobin, in combination with continuous TCD monitoring at the middle cerebral artery, reduced the incidence of advancing stroke and stroke recurrence after treatment without adverse effects in terms of poststroke intracranial hemorrhage.
Topics: Adult; Aged; Batroxobin; Female; Fibrinolytic Agents; Humans; Infusions, Intravenous; Male; Middle Aged; Monitoring, Physiologic; Prognosis; Reference Values; Risk Assessment; Severity of Illness Index; Statistics, Nonparametric; Stroke; Survival Rate; Treatment Outcome; Ultrasonography, Doppler, Transcranial
PubMed: 24684297
DOI: 10.1111/echo.12559 -
Thrombosis Research Sep 1983Experimental disseminated intravascular coagulation (DIC) can be induced by a 4-hr sustained infusion of endotoxin at a dose of 100 mg/kg in rats. This experimental...
Experimental disseminated intravascular coagulation (DIC) can be induced by a 4-hr sustained infusion of endotoxin at a dose of 100 mg/kg in rats. This experimental model of DIC in rats was used to study the effects of defibrinogenation with batroxobin against DIC. One hour before the infusion of endotoxin, 200 batroxobin unit (BU)/kg of batroxobin was injected intraperitoneally. Immediately after the injection, fibrinogen level markedly decreased and fibrinogen and fibrin degradation products increased. Prothrombin time and partial thromboplastin time were also prolonged. Blood counts, platelet counts and hematocrit level only showed a slight decrease after the injection. The preventive effect against DIC was noted by the partial inhibition of the fall in the platelet counts and lessened number of renal glomeruli with fibrin thrombi, in the rats treated with 200 BU/kg of batroxobin 1 hr before the infusion of endotoxin (100 mg/kg/4 hr). From these results, it was shown that fibrinogen metabolism plays an important role in the DIC state.
Topics: Animals; Batroxobin; Blood Coagulation; Disseminated Intravascular Coagulation; Endotoxins; Female; Fibrinogen; Peptide Hydrolases; Rats; Rats, Inbred Strains
PubMed: 6359574
DOI: 10.1016/0049-3848(83)90103-2 -
The Journal of Biological Chemistry Jun 1988We have isolated and analyzed the gene for batroxobin, a thrombin-like snake venom enzyme. Three overlapping DNA segments containing the entire batroxobin gene were...
We have isolated and analyzed the gene for batroxobin, a thrombin-like snake venom enzyme. Three overlapping DNA segments containing the entire batroxobin gene were identified. Sequence analysis revealed that the batroxobin gene spans 8 kilobase pairs and contains five exons. Mature batroxobin is encoded by four separate exons, 2 to 5. The catalytic residues of batroxobin, His-41, Asp-86, and Ser-178, are encoded by separate exons, exons 2, 3, and 5, respectively. The exon/intron organization of the batroxobin gene is different from that of the prothrombin gene but very similar to those of the trypsin and kallikrein genes. These results indicate that batroxobin is not a member of the prothrombin family but one of the trypsin/kallikrein family. The snake venom gland is assumed to originate from the submaxillary gland. Therefore, batroxobin is expected to be a member of the glandular kallikrein family.
Topics: Amino Acid Sequence; Base Sequence; Batroxobin; Crotalid Venoms; DNA; Exons; Introns; Kallikreins; Molecular Sequence Data; Serine Endopeptidases; Trypsin
PubMed: 3163691
DOI: No ID Found -
Advances in Pharmacology and... 1975
Review
Topics: Ancrod; Antineoplastic Agents; Asparaginase; Batroxobin; Brinolase; Bromelains; Chymotrypsin; Deoxyribonucleases; Enzyme Therapy; Enzymes; Fibrinolytic Agents; Humans; Hyaluronoglucosaminidase; Lysostaphin; Microbial Collagenase; Muramidase; Pancreas; Papain; Streptodornase and Streptokinase; Streptokinase; Tissue Extracts; Trypsin; Urokinase-Type Plasminogen Activator
PubMed: 168755
DOI: 10.1016/s1054-3589(08)60222-7 -
Chinese Medical Journal Jun 2004Batroxobin (BX), a serine protease used in defibrinogenation and thrombolysis, also has an effect on c-fos gene and growth factor. This study attempted to determine the...
BACKGROUND
Batroxobin (BX), a serine protease used in defibrinogenation and thrombolysis, also has an effect on c-fos gene and growth factor. This study attempted to determine the effects of BX on the proliferation of vascular smooth muscle cells (VSMCs) and calcium metabolism.
METHODS
VSMCs were treated with BX at concentrations of 0.1, 0.3, or 1.0 mmol/L and cell numbers were determined at 0, 24, 48, and 72 hours. Intracellular calcium concentration ([Ca2+]i) was measured using direct fluorescence methods.
RESULTS
BX was found to suppress proliferation of VSMCs in a dose-dependent fashion with inhibition rates of 18% and 31% by 48 and 72 hours, respectively. In addition, BX decreases basal [Ca2+]i significantly. The basal level in untreated cells was 162.7 +/- 33.8 nmol/L, and decreased to 131.5 +/- 27.7 nmol/L, 128.3 +/- 28.5 nmol/L, and 125.6 +/- 34.3 nmol/L with the three concentrations of BX, respectively. Noradrenaline (NE)-induced [Ca2+]i stimulation was also attenuated by BX (0.1 mmol/L BX, 20% +/- 8% inhibition; 0.3 mmol/L BX, 54% +/- 11% inhibition; 1.0 mmol/L BX, 62% +/- 15% inhibition). The ability of NE to stimulate [Ca2+]i was attenuated in cultures in Ca(2+)-free medium, as was the ability of BX to blunt NE-induced stimulation.
CONCLUSION
These findings demonstrate that BX can effectively inhibit proliferation of VSMCs, probably by blocking the release and uptake of Ca2+, thus influencing [Ca2+]i.
Topics: Animals; Batroxobin; Calcium; Cell Division; Cells, Cultured; Dose-Response Relationship, Drug; Muscle, Smooth, Vascular; Rabbits
PubMed: 15198899
DOI: No ID Found -
Toxicon : Official Journal of the... Apr 2017Recombinant batroxobin is a thrombin-like enzyme of Bothrops atrox moojeni venom. To evaluate its toxicological effect, it was highly expressed in Pichia pastorisand...
Recombinant batroxobin is a thrombin-like enzyme of Bothrops atrox moojeni venom. To evaluate its toxicological effect, it was highly expressed in Pichia pastorisand successfully purified to homogeneity from culture broth supernatant following Good Manufacturing Practice (GMP). The maximum tolerated dose of the recombinant batroxobin was examined in Sprague-Dawley (SD) rat and Beagle dogs following Good Laboratory Practice (GLP) regulations. The approximate lethal dose of recombinant batroxobin was 10 National Institute of Health (NIH) u/kg in male and female rats. Slight test substance-related effects were clearly in male and female dogs at more than 10 NIH u/kg. The maximum tolerated dose (MTD) was considered to be greater than 30 NIH u/kg in dogs. To investigate the repeated dose toxicity of batroxobin, the test item was intravenously administered to groups of SD rat and Beagle dog every day for 4 weeks. We observed that all animals survived the duration of the study without any effects on their mortality. There were no effects in both rats and dogs regarding their clinical signs, body weight, food consumption, ophthalmological examination, urinalysis, hematology, clinical chemistry, organ weightand gross post mortem examinations. The no adverse effect level (NOAEL) of recombinant batroxobin for both males and females is considered to be greater than 2.5 NIH u/kgin rats and 1 NIH u/kg in dogs, respectively. No toxic effects were noted in target organs. In conclusion, these results show a favorable preclinical profile and may contribute clinical development of recombinant batroxobin.
Topics: Animals; Batroxobin; Body Weight; Dogs; Dose-Response Relationship, Drug; Female; Fermentation; Lethal Dose 50; Male; No-Observed-Adverse-Effect Level; Organ Size; Pichia; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Snake Venoms; Thrombin; Toxicity Tests, Acute
PubMed: 28161122
DOI: 10.1016/j.toxicon.2017.01.023 -
Atherosclerosis May 2001The defibrinogenating effect of batroxobin (Defibrase) in male Wistar rats and the inhibitory effects of the plasma of batroxobin-treated rats on the migration of human...
Defibrinogenating effect of batroxobin (Defibrase) in rats and inhibition of migration of human vascular smooth muscle cells by the plasma of batroxobin-treated rats in vitro.
The defibrinogenating effect of batroxobin (Defibrase) in male Wistar rats and the inhibitory effects of the plasma of batroxobin-treated rats on the migration of human vascular smooth muscle cells (SMCs) were investigated in vitro. At 1 h after a single intravenous injection of 3.0, 10.0 or 30.0 BU/kg batroxobin (ten rats in each group), the fibrinogen levels in the plasma of the rats decreased to 88.3, 66.2 and 16.5%, respectively, of that in the plasma of control saline-treated rats (261.0+/-26.7 mg/dl). When the plasma from the batroxobin-treated rats was added to Dulbecco's modified Eagle's medium at a concentration of 0.2% for a vascular SMC migration assay and incubated in a modified Boyden's chamber system at 37 degrees C for 24 h, significant inhibitory effects on vascular SMC migration were observed in the 10.0 (P<0.05) and 30.0 BU/kg (P<0.01) batroxobin-treated rats. The plasma of batroxobin-treated rats as well as standard rat fibrinogen induced vascular SMC migration in a fibrinogen content-dependent manner except the plasma of the 30.0 BU/kg batroxobin-treated rats. Moreover, the rat serum (0.1 approximately 5.0%) did not show any activity on vascular SMC migration in the present experimental system. These results indicate that the plasma fibrinogen significantly influences vascular SMC migration, and that the inhibitory effect of the plasma of batroxobin-treated rats on vascular SMC migration is related to the defibrinogenating action of batroxobin in vivo.
Topics: Animals; Batroxobin; Blood Physiological Phenomena; Cell Movement; Cells, Cultured; Fibrinogen; Fibrinolytic Agents; Humans; Male; Muscle, Smooth, Vascular; Rats; Rats, Wistar
PubMed: 11368999
DOI: 10.1016/s0021-9150(00)00628-6