| enzyme specificity and effects of gyroxin, a serine protease from the venom of the south american rattlesnake crotalus durissus terrificus, on protease-activated receptors. | gyroxin is a serine protease displaying a thrombin-like activity found in the venom of the south american rattlesnake crotalus durissus terrificus. typically, intravenous injection of purified gyroxin induces a barrel rotation syndrome in mice. the serine protease thrombin activates platelets aggregation by cleaving and releasing a tethered n-terminus peptide from the g-protein-coupled receptors, known as protease-activated receptors (pars). gyroxin also presents pro-coagulant activity suggested ... | 2014 | 24412460 |
| is the population of crotalus durissus (serpentes, viperidae) expanding in brazil? | crotalus durissus are found from mexico to northern argentina in a highly disjunct distribution. according to some studies, this species is prone to occupy areas disturbed by human activities and floods comprise a plausible method of dispersal as inferred for some north american rattlesnakes. based on the literature, it seems plausible that crotalus durissus expanded their natural distribution in brazil due to floods, but only in a few municipalities in rio de janeiro state. data entries of buta ... | 2013 | 24314146 |
| inhibition of inducible nitric oxide synthase-derived nitric oxide as a therapeutical target for acute pancreatitis induced by secretory phospholipase a2. | nitric oxide is a key signalling molecule in the pathogenesis of inflammation, but its role in acute pancreatitis and related abdominal pain induced by secretory phospholipase a2 (spla2 ) from crotalus durissus terrificus (cdt) venom has not been investigated. | 2014 | 24166730 |
| structure of the polypeptide crotamine from the brazilian rattlesnake crotalus durissus terrificus. | the crystal structure of the myotoxic, cell-penetrating, basic polypeptide crotamine isolated from the venom of crotalus durissus terrificus has been determined by single-wavelength anomalous dispersion techniques and refined at 1.7 å resolution. the structure reveals distinct cationic and hydrophobic surface regions that are located on opposite sides of the molecule. this surface-charge distribution indicates its possible mode of interaction with negatively charged phospholipids and other molec ... | 2013 | 24100315 |
| biochemical, functional, structural and phylogenetic studies on intercro, a new isoform phospholipase a2 from crotalus durissus terrificus snake venom. | crotoxin is a neurotoxin from crotalus durissus terrificus venom that shows immunomodulatory, anti-inflammatory, antimicrobial, antitumor and analgesic activities. structurally, this toxin is a heterodimeric complex composed by a toxic basic pla2 (crotoxin b or cb) non-covalently linked to an atoxic non-enzymatic and acidic component (crotapotin, crotoxin a or ca). several ca and cb isoforms have been isolated and characterized, showing that the crotoxin venom fraction is, in fact, a mixture of ... | 2013 | 24035779 |
| involvement of formyl peptide receptors in the stimulatory effect of crotoxin on macrophages co-cultivated with tumour cells. | crotoxin (ctx) is the main neurotoxic component of crotalus durissus terrificus snake venom. it inhibits tumour growth and modulates the function of macrophages, which are essential cells in the tumour microenvironment. the present study investigated the effect of ctx on the secretory activity of monocultured macrophages and macrophages co-cultivated with llc-wrc 256 cells. the effect of the macrophage secretory activities on tumour cell proliferation was also evaluated. macrophages pre-treated ... | 2013 | 23998941 |
| daily and seasonal activity patterns of free range south-american rattlesnake (crotalus durissus). | this study aimed at describing daily and seasonal variation in the activity of a population of south-american rattlesnakes (crotalus durissus) in a savanna like habitat (cerrado) in southeastern brazil. seasonal and daily activities of snakes were evaluated by the number of captures of snakes during road surveys, accidental encounters, and relocations by radio-tracking. our results show that climatic variables such as air temperature and rainfall have little influence on the activity pattern of ... | 2013 | 23969850 |
| inhibition of venom serine proteinase and metalloproteinase activities by renealmia alpinia (zingiberaceae) extracts: comparison of wild and in vitro propagated plants. | the plant renealmia alpinia has been used in folk medicine to treat snakebites in the northwest region of colombia. in addition, it has been shown to neutralize edema-forming, hemorrhagic, lethal, and defibrin(ogen)ating activities of bothrops asper venom. in this work, extracts of renealmia alpinia obtained by micropropagation (in vitro) and from specimens collected in the wild were tested and compared in their capacity to inhibit enzymatic and toxic activities of a snake venom metalloproteinas ... | 2013 | 23916793 |
| antinociceptive activity of crotoxin in the central nervous system: a functional magnetic resonance imaging study. | crotoxin, the main neurotoxic component of the venom of south american rattlesnake (crotalus durissus terrificus), is reported to have potent antinociceptive activity. several authors have shown mainly in behavioral pain models that crotoxin induces antinociceptive effects, supposed to be mediated by actions on the central nervous system. the antinociceptive effects of crotoxin (45 μg/kg ip) in rats were verified in this study by increased response latencies in a hargreaves test and tail flick t ... | 2013 | 23916599 |
| description of three new species of hepatozoon (apicomplexa, hepatozoidae) from rattlesnakes (crotalus durissus terrificus) based on molecular, morphometric and morphologic characters. | hepatozoon spp. are commonly found infecting snakes. since the latter are parasitized by diverse forms and data in the literature show divergence, we studied hepatozoon spp. diversity on crotalus durissus terrificus snakes using both molecular and morphological approaches. naturally infected animals were employed. blood was collected, blood smears were prepared and an aliquot was stored at -20°c for dna extraction. five specimens of c. durissus terrificus were selected, each of them infected wit ... | 2013 | 23867148 |
| the evolutionary implications of hemipenial morphology of rattlesnake crotalus durissus terrificus (laurent, 1768) (serpentes: viperidae: crotalinae). | most amniotes vertebrates have an intromittent organ to deliver semen. the reptile sphenodon and most birds lost the ancestral penis and developed a cloaca-cloaca mating. known as hemipenises, the copulatory organ of squamata shows unique features between the amniotes intromittent organ. they are the only paired intromittent organs across amniotes and are fully inverted and encapsulated in the tail when not in use. the histology and ultrastructure of the hemipenes of crotalus durissus rattlesnak ... | 2013 | 23840551 |
| bilateral posterior circulation stroke secondary to a crotalid envenomation: case report. | snake bite envenoming is a disease with potential serious neurological complications. we report a case of an adolescent who was bitten by a rattlesnake and developed bilateral posterior circulation stroke. the rattlesnake was later identified as being crotalus durissus terrificus. stroke was probably due to toxic vasculitis or toxin-induced vascular spasm and endothelial damage. | 2013 | 23740059 |
| coagulopathy as the main systemic manifestation after envenoming by a juvenile south american rattlesnake (crotalus durissus terrificus): case report. | rattlesnake bites in brazil are generally caused by adult individuals, with most of the envenomed patients showing systemic manifestations that include varying degrees of neurotoxicity (acute myasthenia), rhabdomyolysis and coagulopathy, with only mild or no local manifestations. we report a case of envenoming by a juvenile south american rattlesnake (crotalus durissus terrificus) that involved coagulopathy as the main systemic manifestation. | 2013 | 23713821 |
| peripheral kappa and delta opioid receptors are involved in the antinociceptive effect of crotalphine in a rat model of cancer pain. | cancer pain is an important clinical problem and may not respond satisfactorily to the current analgesic therapy. we have characterized a novel and potent analgesic peptide, crotalphine, from the venom of the south american rattlesnake crotalus durissus terrificus. in the present work, the antinociceptive effect of crotalphine was evaluated in a rat model of cancer pain induced by intraplantar injection of walker 256 carcinoma cells. intraplantar injection of tumor cells caused the development o ... | 2013 | 23628488 |
| viperid venom glands with defective venom production. morphological study. | the venom of viperid snakes is collected monthly at butantan institute for research purposes and production of antivenoms. here we describe histological and ultrastructural changes on crotalus durissus terrificus and bothrops sp. venom glands with defective venom production. secretory tubules commonly showed partial or total obliteration of their lumina by masses of necrotic cells and cellular debris. secretory cells showed varying degrees of degenerative and/or metaplastic alterations seriously ... | 2013 | 23583664 |
| characterization of anti-crotalic antibodies. | crotalus durissus terrificus, c. d. collilineatus, c. d. cascavella and c. d. marajoensis are responsible minor but severe snake bites in brazil. the venoms of these snakes share the presence of crotoxin, a neurotoxin comprising of two associated components, crotapotin and phospholipase a2 (pla2). treatment of the victims with specific antiserum is the unique effective therapeutic measure. the ability of anti-crotalus antisera produced by the routine using crude venom to immunize horses or purif ... | 2013 | 23402840 |
| ablation of the ability to control the right-to-left cardiac shunt does not affect oxygen uptake, specific dynamic action or growth in the rattlesnake crotalus durissus. | the morphologically undivided ventricle of the heart in non-crocodilian reptiles permits the mixing of oxygen-rich blood returning from the lungs and oxygen-poor blood from the systemic circulation. a possible functional significance for this intra-cardiac shunt has been debated for almost a century. unilateral left vagotomy rendered the single effective pulmonary artery of the south american rattlesnake, crotalus durissus, unable to adjust the magnitude of blood flow to the lung. the higher con ... | 2013 | 23393283 |
| individual venom profiling of crotalus durissus terrificus specimens from a geographically limited region: crotamine assessment and captivity evaluation on the biological activities. | crotalus durissus terrificus (cdt) venom major components comprise crotoxin, crotamine, gyroxin and convulxin. crotamine exerts a myotoxic action, among others, but its expression varies even amid snakes from the same region. biochemical, enzymatic and pharmacological variations of venoms may be associated with the geography, climate, gender, age, and diet, as well as captivity time and venom extraction intervals. the present study aimed to characterize the cdt venom from the botucatu region, (s ... | 2013 | 23380403 |
| inhibitory effect of crotalus durissus terrificus venom on chronic edema induced by injection of bacillus calmette-guérin into the footpad of mice. | in this study, we evaluated the effect of the crotalus durissus terrificus (cdt) venom on the chronic paw edema induced by the injection of bacillus calmette-guérin (bcg) into the footpad of mice. the bcg injection evoked chronic edema, which was significantly diminished in animals treated subcutaneously (s.c.) with cdt venom 1 h before or after the bcg injection. this inhibition persisted throughout the evaluation period (15 days). in mice injected with cdt venom 6 or 11 days after injection of ... | 2013 | 23246578 |
| growth inhibitory effects and molecular mechanisms of crotoxin treatment in esophageal eca-109 cells and transplanted tumors in nude mice. | to investigate the antitumor actions of the crotalus durissus neurotoxin (crotoxin) on human esophageal carcinoma (eca-109) cells in vitro and transplanted esophageal eca-109 tumors in nude mice. | 2013 | 23202800 |
| dna-interactive properties of crotamine, a cell-penetrating polypeptide and a potential drug carrier. | crotamine, a 42-residue polypeptide derived from the venom of the south american rattlesnake crotalus durissus terrificus, has been shown to be a cell-penetrating protein that targets chromosomes, carries plasmid dna into cells, and shows specificity for actively proliferating cells. given this potential role as a nucleic acid-delivery vector, we have studied in detail the binding of crotamine to single- and double-stranded dnas of different lengths and base compositions over a range of ionic co ... | 2012 | 23145017 |
| crotoxin, a rattlesnake toxin, induces a long-lasting inhibitory effect on phagocytosis by neutrophils. | crotalus durissus terrificus snake venom (cdtv) has long-lasting anti-inflammatory properties and inhibits the spreading and phagocytic activity of macrophages. crotoxin (ctx), the main component of cdtv, is responsible for these effects. considering the role of neutrophils in the inflammatory response and the lack of information about the effect of cdtv on neutrophils, the aim of this study was to investigate the effect of cdtv and ctx on two functions of neutrophils, namely phagocytosis and pr ... | 2012 | 23045721 |
| purification, crystallization and preliminary x-ray diffraction analysis of crotamine, a myotoxic polypeptide from the brazilian snake crotalus durissus terrificus. | crotamine, a highly basic myotoxic polypeptide (molecular mass 4881 da) isolated from the venom of the brazilian rattlesnake crotalus durissus terrificus, causes skeletal muscle contraction and spasms, affects the functioning of voltage-sensitive sodium channels by inducing sodium influx and possesses antitumour activity, suggesting potential pharmaceutical applications. crotamine was purified from c. durissus terrificus venom; the crystals diffracted to 1.9 å resolution and belonged to the orth ... | 2012 | 22949192 |
| isolation, enzymatic characterization and antiedematogenic activity of the first reported rattlesnake hyaluronidase from crotalus durissus terrificus venom. | a hyaluronidase (cdthya1) from crotalus durissus terrificus snake venom (cdtv) was isolated and showed to exhibit a high activity on hyaluronan cleavage. however, surveys on this enzyme are still limited. this study aimed at its isolation, functional/structural characterization and the evaluation of its effect on the spreading of crotoxin and phospholipase a(2) (pla(2)). the enzyme was purified through cation exchange, gel filtration and hydrophobic chromatography. after that, it was submitted t ... | 2012 | 22940594 |
| kinetic characterization of gyroxin, a serine protease from crotalus durissus terrificus venom. | this work describes for the first time the characterization of the enzymatic features of gyroxin, a serine protease from crotalus durissus terrificus venom, capable to induce barrel rotation syndrome in rodents. measuring the hydrolysis of the substrate zfr-mca, the optimal ph for proteolytic cleavage of gyroxin was found to be at ph 8.4. increases in the hydrolytic activity were observed at temperatures from 25 °c to 45 °c, and increases of nacl concentration up to 1 m led to activity decreases ... | 2012 | 22898589 |
| lmrtx, a basic pla₂ (d49) purified from lachesis muta rhombeata snake venom with enzymatic-related antithrombotic and anticoagulant activity. | a basic phospholipase a₂ (lmrtx) isoform was isolated from lachesis muta rhombeata snake venom and partially characterized. the venom was fractionated by molecular exclusion chromatography in ammonium bicarbonate buffer followed by reverse-phase hplc on a c-5 discovery® bio wide column. from liquid chromatography-electrospray ionization/mass spectrometry, the molecular mass of lmrtx was measured as 14.277.50 da. the amino acid sequence showed a high degree of homology between pla₂ lmrtx from l. ... | 2012 | 22750534 |
| crystallographic characterization of functional sites of crotoxin and ammodytoxin, potent β-neurotoxins from viperidae venom. | this review will focus on a description of the three-dimensional structures of two β-neurotoxins, the monomeric pla(2) ammodytoxin from vipera ammodytes ammodytes, and heterodimeric crotoxin from crotalus durissus terrificus, and a detailed structural analysis of their multiple functional sites. we have recently determined at high resolution the crystal structures of two natural isoforms of ammodytoxin (atxa and atxc) (saul et al., 2010) which exhibit different toxicity profiles and different an ... | 2012 | 22683534 |
| [experimental efficacy of igy antibodies produced in eggs against the venom of the peruvian snake bothrops atrox]. | to develop an immunization protocol in order to produce avian igy immunoglobulins against bothrops atrox peruvian snake venom and to evaluate its neutralizing capacity. | 2012 | 22510909 |
| characterization of two vasoactive peptides isolated from the plasma of the snake crotalus durissus terrificus. | incubation of plasma from the snake crotalus durissus terrificus (cdtp) with trypsin generated two hypotensive peptides. the primary structure of the peptides was established for two sequences as: (ser-ile-pro-gln-ala-pro-thr-ser-asn-leu-ile-glu-ala-thr-lys) and (lys-pro-asp-ala-asn-gln-val-leu-ile-gln-val-ile-gly-val). these peptides display homology with fragments of albumin from trimeresurus flavoviridis. bolus intra-arterial injection of the purified or the synthetic peptide produced a stron ... | 2012 | 22483415 |
| relationship between the structure and the enzymatic activity of crotoxin complex and its phospholipase a2 subunit: an in silico approach. | crotoxin, one of the major toxins of south american rattlesnake crotalus durissus subspecies, is an heterodimeric complex composed of two distinct subunits: a basic phospholipase a(2) (pla(2), cb) and an acidic nontoxic catalytically inactive protein, crotapotin (ca). it's well known that cb has a high enzymatic activity; however the molecular aspects that determine this fact remain unknown. in this study, an in silico approach was used to predict the ca structure by homology modeling, and the c ... | 2012 | 22481077 |
| envenomations by bothrops and crotalus snakes induce the release of mitochondrial alarmins. | skeletal muscle necrosis is a common manifestation of viperid snakebite envenomations. venoms from snakes of the genus bothrops, such as that of b. asper, induce muscle tissue damage at the site of venom injection, provoking severe local pathology which often results in permanent sequelae. in contrast, the venom of the south american rattlesnake crotalus durissus terrificus, induces a clinical picture of systemic myotoxicity, i.e., rhabdomyolysis, together with neurotoxicity. it is known that mo ... | 2012 | 22363828 |
| clinical safety evaluation of f(ab')₂ antivenom (crotalus durissus-bothrops asper) administration in dogs. | antivenoms consisting of selective antigen binding antibody fragments, or f(ab')(2), are becoming more popular in human and veterinary medicine, owing to their preferred kinetics, tissue distribution, and removal of the fc binding portion of igg. consequences of antivenom administration can include acute and delayed reactions, dependent, in part, on the antivenom's donor source, purity, and composition. this study evaluated an equine-derived polyvalent f(ab')(2) pit viper antivenom in healthy do ... | 2011 | 22316205 |
| crotamine, a small basic polypeptide myotoxin from rattlesnake venom with cell-penetrating properties. | crotamine, a low molecular weight cationic polypeptide from the venom of the south american rattlesnake crotalus durissus terrificus is a natural cell-penetrating peptide with functional versatility. the presence of nine lysine residues and three disulfide bonds renders crotamine highly compact, stable and positively charged. topologically, crotamine adopts an ancient β-defensin fold that is found in diverse families of endogenous and venom polypeptides dedicated to host defense. crotamine is un ... | 2011 | 22204433 |
| immunohistochemical and functional characterization of nitric oxide signaling pathway in isolated aorta from crotalus durissus terrificus. | we characterized the nitric oxide (no)-cyclic gmp-phosphodiesterase-5 (pde5) pathway in crotalus durissus terrificus aorta. concentration responses curves to acetylcholine (ach), sodium nitroprusside (snp), bay41-2272 (soluble guanylyl cyclase [sgc] stimulator), bay60-2770 (sgc activator) and tadalafil (pde5 inhibitor) were constructed in phenylephrine (10 μm)-precontracted tissues with intact (e(+)) or denuded (e(-)) endothelium. ach (0.0001-10 μm) and snp (0.0001-10 μm) relaxed aorta, which we ... | 2012 | 22134054 |
| crotoxin and phospholipases a₂ from crotalus durissus terrificus showed antiviral activity against dengue and yellow fever viruses. | dengue is the most important arbovirus in the world with an estimated of 50 million dengue infections occurring annually and approximately 2.5 billion people living in dengue endemic countries. yellow fever is a viral hemorrhagic fever with high mortality that is transmitted by mosquitoes. effective vaccines against yellow fever have been available for almost 70 years and are responsible for a significant reduction of occurrences of the disease worldwide; however, approximately 200,000 cases of ... | 2012 | 21723310 |
| role of a novel tetrodotoxin-resistant sodium channel in the nitrergic relaxation of corpus cavernosum from the south american rattlesnake crotalus durissus terrificus. | coitus in snakes may last up to 28 hours; however, the mechanisms involved are unknown. | 2011 | 21477017 |
| biological versatility of crotamine--a cationic peptide from the venom of a south american rattlesnake. | molecules isolated from animals, insects, plants or microorganisms can provide prototypes for design of biopharmaceutical products. some venom toxins and their derivatives are used in medicine, while others provide templates for development of new drugs. | 2010 | 21062230 |
| the heart of the south american rattlesnake, crotalus durissus. | most anatomical and physiological studies of the sauropsid heart have focused on species with extraordinary physiologies, and detailed anatomical descriptions of hearts from sauropsids with more common physiologies are therefore warranted. here, we present a comprehensive study of the cardiac anatomy of the south american rattlesnake (crotalus durissus). the cardiovascular physiology of this species has been investigated in a number of studies, whereas only a few cursory studies exist on the car ... | 2010 | 20730920 |
| successful treatment of south american rattlesnake (crotalus durissus terrificus) envenomation with crotalidae polyvalent immune fab (crofab™). | | 2011 | 20658221 |
| snake venomics of bothriechis nigroviridis reveals extreme variability among palm pitviper venoms: different evolutionary solutions for the same trophic purpose. | we report the proteomic characterization and biological activities of the venom of the black-speckled palm pitviper, bothriechis nigroviridis, a neotropical arboreal pitviper from costa rica. in marked contrast to other bothriechis species investigated, the venom of b. nigroviridis does not possess detectable zn(2+)-dependent metalloproteinases, and is uniquely characterized by a high content of crotoxin-like pla(2) and vasoactive peptides. these data suggest that different evolutionary solution ... | 2010 | 20590130 |
| snake venomic of crotalus durissus terrificus--correlation with pharmacological activities. | the snake venomic of crotalus durissus terrificus was analyzed by 2-d and 1-d electrophoresis and subsequent ms/ms and enzymatic assays. the venomic of the south american rattlesnake comprises toxins from seven protein families: phospholipases a(2), serine proteinases, ecto-5'-nucleotidases, metalloproteinases, nerve growth factors, phosphodiesterases, and glutaminyl cyclase. the venom toxin composition correlates with the clinical manifestation of the crotalinae snake bites and explains patholo ... | 2010 | 20205475 |
| crotoxin: novel activities for a classic beta-neurotoxin. | crotoxin, the main toxin of south american rattlesnake (crotalus durissus terrificus) venom, was the first snake venom protein to be purified and crystallized. crotoxin is a heterodimeric beta-neurotoxin that consists of a weakly toxic basic phospholipase a(2) and a non-enzymatic, non-toxic acidic component (crotapotin). the classic biological activities normally attributed to crotoxin include neurotoxicity, myotoxicity, nephrotoxicity and cardiotoxicity. however, numerous studies in recent year ... | 2010 | 20109480 |
| crystallization and preliminary x-ray diffraction analysis of crotoxin b from crotalus durissus collilineatus venom. | crotoxin b is a basic phospholipase a(2) found in the venom of several crotalus durissus ssp. rattlesnakes and is one of the subunits that constitute crotoxin, the main component of the venom of these snakes. this heterodimeric toxin is related to important envenomation effects such as neurological disorders, myotoxicity and renal failure. although crotoxin was first crystallized in 1938, the first structural data only became available in 2007 (for crotoxin b from c. durissus terrificus) and sho ... | 2009 | 19851009 |
| snake venomics and antivenomics of bothrops colombiensis, a medically important pitviper of the bothrops atrox-asper complex endemic to venezuela: contributing to its taxonomy and snakebite management. | the taxonomic status of the medically important pitviper of the bothrops atrox-asper complex endemic to venezuela, which has been classified as bothrops colombiensis, remains incertae cedis. to help resolving this question, the venom proteome of b. colombiensis was characterized by reverse-phase hplc fractionation followed by analysis of each chromatographic fraction by sds-page, n-terminal sequencing, maldi-tof mass fingerprinting, and collision-induced dissociation tandem mass spectrometry of ... | 2009 | 19457355 |
| crotalus durissus collilineatus venom gland transcriptome: analysis of gene expression profile. | crotalus durissus rattlesnakes are responsible for the most lethal cases of snakebites in brazil. crotalus durissus collilineatus subspecies is related to a great number of accidents in southeast and central west regions, but few studies on its venom composition have been carried out to date. in an attempt to describe the transcriptional profile of the c. durissus collilineatus venom gland, we generated a cdna library and the sequences obtained could be identified by similarity searches on exist ... | 2009 | 19230843 |
| peptidase activities in the semen from the ductus deferens and uterus of the neotropical rattlesnake crotalus durissus terrificus. | to understand the role of peptidases in seminal physiology of crotalus durissus terrificus, intra- and inter-seasonal activity levels of acid (apa), basic (apb), puromycin-sensitive (apn-ps) and puromycin-insensitive neutral (apn-pi), cystyl (cap), dipeptidyl-iv (dppiv), type-1 pyroglutamyl (pap-i) and prolyl-imino (pip) aminopeptidases as well as prolyl endopeptidase (pop) were evaluated in soluble (sf) and/or membrane-bound (mf) fractions of semen collected from the ductus deferens of the male ... | 2009 | 19225781 |
| the unequal influences of the left and right vagi on the control of the heart and pulmonary artery in the rattlesnake, crotalus durissus. | autonomic control of the cardiovascular system in reptiles includes sympathetic components but heart rate (f(h)), pulmonary blood flow (q(pul)) and cardiac shunt patterns are primarily controlled by the parasympathetic nervous system. the vagus innervates both the heart and a sphincter on the pulmonary artery. the present study reveals that whereas both the left and right vagi influence f(h), it is only the left vagus that influences pulmonary vascular resistance. this is associated with the fac ... | 2009 | 19088220 |
| seasonal variation of peptidase activities in the reproductive tract of crotalus durissus terrificus. | seasonal quantitative patterns of acid (apa), basic (apb), puromycin-sensitive (apn-ps) and puromycin-insensitive neutral (apn-pi), cystyl (cap), dipeptidyl iv (dppiv), type-1 pyroglutamyl (pap-i) and prolyl-imino (pip) aminopeptidases and prolyl oligopeptidase (pop) activities in soluble (sf) and solubilized membrane-bound (mf) fractions from ductus deferens, vagina and uterus were studied to evaluate their relationships with the reproductive cycle and the extensive long-term spermatozoa storag ... | 2009 | 19027015 |
| physiological importance of the coronary arterial blood supply to the rattlesnake heart. | the reptilian heart consists of a thick inner spongy myocardium that derives its oxygen and nutrient supply directly from the blood within the ventricular cavity, which is surrounded by a thin outer compact layer supplied by coronary arteries. the functional importance of these coronary arteries remains unknown. in the present study we investigate the effects of permanent coronary artery occlusion in the south american rattlesnake (crotalus durissus) on the ability to maintain heart rate and blo ... | 2008 | 18978223 |
| expression of mrnas coding for vap1/crotastatin-like metalloproteases in the venom glands of three south american pit vipers assessed by quantitative real-time pcr. | snake venom metalloproteases encompass a large family of toxins, with approximately 200 members already catalogued, which exhibit a diversity of structures and biological functions. from this relatively large number, only a dozen examples of apoptosis-inducing metalloproteases, like vap1 and 2 from the venom of crotalus atrox, are known. since most vap1-like toxins ever characterized were purified from the venom of viperidae species inhabiting diverse places on earth, we investigate the expressi ... | 2008 | 18926840 |
| anti-platelet effect of cumanastatin 1, a disintegrin isolated from venom of south american crotalus rattlesnake. | disintegrins have been previously described in the venom of several snake families inhibiting signal transduction, cell-cell interactions, and cell-matrix interactions and may have therapeutic potential in heart attacks, thrombotic diseases, and cancers. this investigation describes the first disintegrin isolated from south american crotalus venom (venezuelan rattlesnake crotalus durissus cumanensis), which inhibits platelet adhesion to matrix proteins. c. d. cumanensis crude venom was first sep ... | 2009 | 18835011 |
| peptidase activities in crotalus durissus terrificus semen. | | 2008 | 18784247 |
| pulmonary mechanic and lung histology injury induced by crotalus durissus terrificus snake venom. | in the present work we investigated the effects of crotalus durissus terrificus venom (cdtv) on the pulmonary mechanic events [static and dynamic elastance, resistive (deltap1) and viscoelastic pressures (deltap2)] and histology after intramuscular injection of saline solution (control) or venom (0.6 microg/g). the static and dynamic elastance values were increased significantly after 3 h of venom inoculation, but were reduced at control values in the other periods studied. the deltap1 values th ... | 2008 | 18457854 |
| insights into the role of oligomeric state on the biological activities of crotoxin: crystal structure of a tetrameric phospholipase a2 formed by two isoforms of crotoxin b from crotalus durissus terrificus venom. | crotoxin b (cb or cdt pla(2)) is a basic asp49-pla(2) found in the venom of crotalus durissus terrificus and it is one of the subunits that constitute the crotoxin (cro). this heterodimeric toxin, main component of the c. d. terrificus venom, is completed by an acidic, nontoxic, and nonenzymatic component (crotoxin a, ca or crotapotin), and it is related to important envenomation effects such as neurological disorders, myotoxicity, and renal failure. although cro has been crystallized since 1938 ... | 2008 | 18275084 |
| preliminary x-ray crystallographic studies of a tetrameric phospholipase a2 formed by two isoforms of crotoxin b from crotalus durissus terrificus venom. | crotoxin b is a basic phospholipase a2 found in the venom of crotalus durissus terrificus and is one of the subunits that constitute crotoxin. this heterodimeric toxin, which is the main component of c. d. terrificus venom, is completed by an acidic, nontoxic and non-enzymatic component (crotoxin a) and is involved in important envenomation effects, such as neurological disorders, myotoxicity and renal failure. although crotoxin was first crystallized in 1938, no crystal structure is currently a ... | 2007 | 18084096 |
| the adrenergic regulation of the cardiovascular system in the south american rattlesnake, crotalus durissus. | the present study investigates adrenergic regulation of the systemic and pulmonary circulations of the anaesthetised south american rattlesnake, crotalus durissus. haemodynamic measurements were made following bolus injections of adrenaline and adrenergic antagonists administered through a systemic arterial catheter. adrenaline caused a marked systemic vasoconstriction that was abolished by phentolamine, indicating this response was mediated through alpha-adrenergic receptors. injection of phent ... | 2007 | 17669676 |
| crotamine mediates gene delivery into cells through the binding to heparan sulfate proteoglycans. | recently we have shown that crotamine, a toxin from the south american rattlesnake crotalus durissus terrificus venom, belongs to the family of cell-penetrating peptides. moreover, crotamine was demonstrated to be a marker of centrioles, of cell cycle, and of actively proliferating cells. herein we show that this toxin at non-toxic concentrations is also capable of binding electrostatically to plasmid dna forming dna-peptide complexes whose stabilities overcome the need for chemical conjugation ... | 2007 | 17491023 |
| crystallization and preliminary x-ray crystallographic analysis of the heterodimeric crotoxin complex and the isolated subunits crotapotin and phospholipase a2. | crotoxin, a potent neurotoxin from the venom of the south american rattlesnake crotalus durissus terrificus, exists as a heterodimer formed between a phospholipase a(2) and a catalytically inactive acidic phospholipase a(2) analogue (crotapotin). large single crystals of the crotoxin complex and of the isolated subunits have been obtained. the crotoxin complex crystal belongs to the orthorhombic space group p2(1)2(1)2, with unit-cell parameters a = 38.2, b = 68.7, c = 84.2 a, and diffracted to 1 ... | 2007 | 17401196 |
| withdrawn: microvesicles in the venom of crotalus durissus terrificus (serpentes, viperidae). | the publisher regrets that this article was an accidental duplication of an article that has already been published in toxicon, 49 (2007) 106-110, . the duplicate article has therefore been withdrawn. | 2006 | 17161856 |
| microvesicles in the venom of crotalus durissus terrificus (serpentes, viperidae). | microvesicles with electron-dense content are consistently observed by transmission electron microscopy on the luminal face of secretory cells of venom glands of viperid snakes. in this work, we evaluated their presence in crotalus durissus terrificus venom glands and also in freshly collected venom. microvesicles were found in the venom glands mainly in regions of exocytosis. they ranged from 40 to 80 nm in diameter. freeze-fracture replicas of the glands revealed particles on the cytoplasmic l ... | 2007 | 17084429 |
| evidence for a respiratory component, similar to mammalian respiratory sinus arrhythmia, in the heart rate variability signal from the rattlesnake, crotalus durissus terrificus. | autonomic control of heart rate variability and the central location of vagal preganglionic neurones (vpn) were examined in the rattlesnake (crotalus durissus terrificus), in order to determine whether respiratory sinus arrhythmia (rsa) occurred in a similar manner to that described for mammals. resting ecg signals were recorded in undisturbed snakes using miniature datalogging devices, and the presence of oscillations in heart rate (fh) was assessed by power spectral analysis (psa). this mathem ... | 2006 | 16809454 |
| characterization of a new platelet aggregating factor from crotoxin crotalus durissus cascavella venom. | in this article we investigated the platelet aggregating activity of whole crotoxin and its subunits isolated from crotalus durissus cascavella venom. during the purification protocols of the venom, using hplc molecular exclusion, we detected the presence of two different serine protease activities in the gyroxin fraction, and another in the crotoxin fraction, which induced strong and irreversible platelet aggregation, in addition to blood coagulation. from crotoxin, we isolated pla2, crotapotin ... | 2006 | 16729248 |
| gastroesophageal reflux in healthy subjects induced by two different species of chilli (capsicum annum). | although the ingestion of chilli has been associated with gastroesophageal reflux (ger) symptoms, there are no studies that have explored the effect of a chronic ingestion of different kinds of chilli with a variable content of capsaicin as a cause of ger. | 2006 | 16699276 |
| crotacetin, a novel snake venom c-type lectin homolog of convulxin, exhibits an unpredictable antimicrobial activity. | snake venom (sv) c-type lectins encompass a group of hemorrhagic toxins that are capable of interfering with blood stasis. a very well-studied svc-type lectin is the heterodimeric toxin, convulxin (cvx), from the venom of south american rattlesnake crotalus durissus terrificus. cvx is able to activate platelets and induce their aggregation by acting via p62/gpvi collagen receptor. by using polymerase chain reaction homology screening, we have cloned several cdna precursors of cvx subunit homolog ... | 2006 | 16679528 |
| arterial acid-base status during digestion and following vascular infusion of nahco(3) and hcl in the south american rattlesnake, crotalus durissus. | digestion is associated with gastric secretion that leads to an alkalinisation of the blood, termed the "alkaline tide". numerous studies on different reptiles and amphibians show that while plasma bicarbonate concentration ([hco(3)(-)](pl)) increases substantially during digestion, arterial ph (pha) remains virtually unchanged, due to a concurrent rise in arterial pco(2) (paco(2)) caused by a relative hypoventilation. this has led to the suggestion that postprandial amphibians and reptiles regu ... | 2005 | 16289770 |
| automated nmr structure determination and disulfide bond identification of the myotoxin crotamine from crotalus durissus terrificus. | crotamine is one of four major components of the venom of the south american rattlesnake crotalus durissus terrificus. similar to its counterparts in the family of the myotoxins, it induces myonecrosis of skeletal muscle cells. this paper describes a new nmr structure determination of crotamine in aqueous solution at ph 5.8 and 20 degrees c, using standard homonuclear 1h nmr spectroscopy at 900mhz and the automated structure calculation software atnos/candid/dyana. the automatic noesy spectral a ... | 2005 | 16185738 |
| biochemical and enzymatic characterization of two basic asp49 phospholipase a2 isoforms from lachesis muta muta (surucucu) venom. | two basic phospholipase a2 (pla2) isoforms were isolated from lachesis muta muta snake venom and partially characterized. the venom was fractionated by molecular exclusion chromatography in ammonium bicarbonate buffer followed by reverse-phase hplc on a c-18 mu-bondapack column and rp-hplc on a c-8 column. from liquid chromatography-electrospray ionization/mass spectrometry, the molecular mass of the two isoforms lmtx-i and lmtx-ii was respectively measured as 14,245.4 and 14,186.2 da. the pi wa ... | 2005 | 16005152 |
| hypoxic pulmonary vasoconstriction in reptiles: a comparative study of four species with different lung structures and pulmonary blood pressures. | low o2 levels in the lungs of birds and mammals cause constriction of the pulmonary vasculature that elevates resistance to pulmonary blood flow and increases pulmonary blood pressure. this hypoxic pulmonary vasoconstriction (hpv) diverts pulmonary blood flow from poorly ventilated and hypoxic areas of the lung to more well-ventilated parts and is considered important for the local matching of ventilation to blood perfusion. in the present study, the effects of acute hypoxia on pulmonary and sys ... | 2005 | 15961533 |
| crotalidae polyvalent immune fab (ovine) antivenom is effective in the neutralization of south american viperidae venoms in a murine model. | crotalidae polyvalent immune fab (ovine) (crofab; fabav) is used in the treatment of symptomatic crotaline envenomations in north america. unlike antivenin (crotalidae) polyvalent, which is approved for treatment of crotaline envenomation in north and south america, fabav is manufactured using only venoms from crotaline snakes native to the united states. this study was designed to evaluate the efficacy of fabav in the neutralization of venom from 2 south american crotaline snakes: crotalus duri ... | 2005 | 15940091 |
| on the unsual hemorrhagic and necrotic activities caused by the rattlesnake (crotalus durissus cumanensis) in a venezuelan patient. | the hemorrhagic, necrotic and edematous effects observed in a 23-year-old patient from lagunetica, los teques, state of miranda, venezuela, that was bitten by a common venezuelan rattlesnake (crotalus durissus cumanensi), were described. the patient was treated with polyvalente serum, antibiotics and autograft. this finding allows to suggest that the poison of some venezuelan common rattlesnakes has a systemic effect on the skeletal muscle and on capillaries that generate edema, hemorragic pheno ... | 2009 | 15849951 |
| tracing an invasion: landbridges, refugia, and the phylogeography of the neotropical rattlesnake (serpentes: viperidae: crotalus durissus). | abstract pleistocene fragmentation of the amazonian rainforest has been hypothesized to be a major cause of neotropical speciation and diversity. however, the role and even the reality of pleistocene forest refugia have attracted much scepticism. in amazonia, previous phylogeographical studies have focused mostly on organisms found in the forests themselves, and generally found speciation events to have predated the pleistocene. however, molecular studies of open-formation taxa found both north ... | 2005 | 15773938 |
| the role of nitric oxide in the regulation of the systemic and pulmonary vasculature of the rattlesnake, crotalus durissus terrificus. | the functional role of nitric oxide (no) was investigated in the systemic and pulmonary circulations of the south american rattlesnake, crotalus durissus terrificus. bolus, intra-arterial injections of the no donor, sodium nitroprusside (snp) caused a significant systemic vasodilatation resulting in a reduction in systemic resistance (rsys). this response was accompanied by a significant decrease in systemic pressure and a rise in systemic blood flow. pulmonary resistance (rpul) remained constan ... | 2005 | 15726384 |
| acute renal failure after crotalus durissus snakebite: a prospective survey on 100 patients. | acute renal failure (arf) is the main cause of death after the south american crotalid snakebite. the aim of this study was to assess the prevalence, risk factors, and characteristics of crotalus durissus venom-induced arf. | 2005 | 15673314 |
| reproductive cycle of the neotropical crotalus durissus terrificus: ii. establishment and maintenance of the uterine muscular twisting, a strategy for long-term sperm storage. | crotaline snakes store sperm by means of a uterine musculature twisting (umt). we investigated the influence of plasma levels of estradiol and progesterone and vasotocinase cystine aminopeptidase (cap) activity on umt formation and maintenance, and the in vitro uterine reactivity for avt in crotalus durissus terrificus in primary or secondary vitellogenesis with or without umt. frequency of females in secondary vitellogenesis with umt is significantly higher than in primary one. estradiol levels ... | 2004 | 15504393 |
| reproductive cycle of the neotropical crotalus durissus terrificus: i. seasonal levels and interplay between steroid hormones and vasotocinase. | crotaline snakes present delayed fertilization and sperm storage because secondary vitellogenesis is not completed by the time of mating. the release of vitellogenesis and synchrony between ovulation and fertilization suggest a steroidal modulation. we investigated changes of sexual steroid levels during reproduction in the neotropical rattlesnake crotalus durissus terrificus, analyzing macroscopical variations of reproductive condition (vitellogenesis, pregnancy, and post-partum) and plasma lev ... | 2004 | 15504392 |
| immunosuppresive role of principal toxin (crotoxin) of crotalus durissus terrificus venom. | the composition of the crotalic venom and the immunochemistry and/or pathophysiological characterization and main components were well studied. however, few studies have been carried out to investigate the effect of toxins of this venom on the development of the immune response. the objective of this work was to find out if venom or crotoxin of crotalus durissus terrificus was able to modulate the immune response through its ability to change the mediators involved in the immune response by an u ... | 2004 | 15501286 |
| cardiovascular actions of rattlesnake bradykinin ([val1,thr6]bradykinin) in the anesthetized south american rattlesnake crotalus durissus terrificus. | incubation of heat-denatured plasma from the rattlesnake crotalus atrox with trypsin generated a bradykinin (bk) that contained two amino acid substitutions (arg1 --> val and ser6 --> thr) compared with mammalian bk. bolus intra-arterial injections of synthetic rattlesnake bk (0.01-10 nmol/kg) into the anesthetized rattlesnake, crotalus durissus terrificus, produced a pronounced and concentration-dependent increase in systemic vascular conductance (gsys). this caused a fall in systemic arterial ... | 2005 | 15498967 |
| the ventilatory response to environmental hypercarbia in the south american rattlesnake, crotalus durissus. | to study the effects of environmental hypercarbia on ventilation in snakes, particularly the anomalous hyperpnea that is seen when co(2) is removed from inspired gas mixtures (post-hypercapnic hyperpnea), gas mixtures of varying concentrations of co(2) were administered to south american rattlesnakes, crotalus durissus, breathing through an intact respiratory system or via a tracheal cannula by-passing the upper airways. exposure to environmental hypercarbia at increasing levels, up to 7% co(2), ... | 2004 | 14767598 |
| structure and chromosomal localization of the gene for crotamine, a toxin from the south american rattlesnake, crotalus durissus terrificus. | crotamine is a 42 amino acid-long basic polypeptide, one of the major components of the south american rattlesnake, crotalus durissus terrificus, venom. the mrna has about 340 nucleotides and codifies a pre-crotamine, including the signal peptide, the mature crotamine, and a final lysine. in this report, we describe the crotamine gene with 1.8 kb organized into three exons separated by a long phase-1 (900 bp) and a short phase-2 (140 bp) introns. exon 1 includes the 5'-untranslated region and co ... | 2003 | 14757205 |
| absence of myocardial involvement in children victims of crotalus durissus terrificus envenoming. | the myotoxic activity of the venom of crotalus durissus terrificus is demonstrable by increased serum levels of the enzymes creatine kinase (ck), lactate dehydrogenase (ld), and aspartate aminotransferase. serial measurements of ck, ld and their isoenzymes in bite victims showed a pattern similar to that observed in acute myocardial infarction, although the clinical course and electro- and echocardiographic data did not suggest cardiac involvement. these data have raised the hypothesis that crot ... | 2003 | 14757204 |
| direct organogenesis of mandevilla illustris (vell) woodson and effects of its aqueous extract on the enzymatic and toxic activities of crotalus durissus terrificus snake venom. | in order to produce explants of mandevilla illustris (vell) woodson for the "cerrado in vitro", the germplasm bank of unaerp, we carried out a micropropagation protocol using ms or ms/3 medium supplemented with different concentrations of 6-benzyladeninepurine (ba), zeatin or 2-isopentenyladenine for nodal segment growth, and alpha-naphthaleneacetic acid, indole-3-butyric acid (iba) or 1,4 dithiothreitol for rooting. for nodal segments, all the cytokinins tested yielded similar results. however, ... | 2004 | 14727051 |
| the thermogenesis of digestion in rattlesnakes. | some snakes have a feeding regime characterized by the infrequent ingestion of relatively large meals, causing impressive increments in post-prandial metabolism. metabolism remains elevated for many days, while digestion proceeds, resulting in considerable investment of time and energy. snakes actively adjust thermoregulatory behavior to raise their body temperature during digestion, exhibiting a post-prandial thermophilic response that accelerates digestion at the expense of higher metabolic ra ... | 2004 | 14718501 |
| inhibition of enzymatic and pharmacological activities of some snake venoms and toxins by mandevilla velutina (apocynaceae) aqueous extract. | phospholipases a(2) (pla(2)) are multifunctional proteins which exhibit varied biological activities correlated to the structural diversities of the sub-classes. the crude aqueous extract from subterranean system of mandevilla velutina, a plant found in brazilian savanna, was assayed for its ability to inhibit biological activities of several snake venoms and isolated pla(2)s. the extract induced total inhibition of the phospholipase activity of crotalus durissus terrificus venom and only partia ... | 2003 | 14644557 |
| crystal structure of the platelet activator convulxin, a disulfide-linked alpha4beta4 cyclic tetramer from the venom of crotalus durissus terrificus. | convulxin (cvx), a c-type lectin, isolated from the venom of the south american rattlesnake crotalus durissus terrificus, causes cardiovascular and respiratory disturbances and is a potent platelet activator which binds to platelet glycoprotein gpvi. the structure of cvx has been solved at 2.4a resolution to a crystallographic residual of 18.6% (r(free)=26.4%). cvx is a disulfide linked heterodimer consisting of homologous alpha and beta chains. the heterodimers are additionally linked by disulf ... | 2003 | 14521935 |
| crotapotin induced modification of t lymphocyte proliferative response through interference with pge2 synthesis. | the immunosuppressive property has been demonstrated for the venom of the crotalus durissus terrificus. using a simple, novel method for obtaining crotapotin and phospholipase a2 isoforms from venom, it was possible to demonstrate that the addition of crotapotin to cultures of isolated lymphocytes resulted in a significant inhibition of the cellular proliferative response to concanavalin a. this reduction in blastogenic response of lymphocytes is accompanied by a significant increase in the prod ... | 2003 | 14505945 |
| initial structural analysis of an alpha4beta4 c-type lectin from the venom of crotalus durissus terrificus. | convulxin, an alphabeta c-type lectin, is a potent platelet activator isolated from the venom of the south american rattlesnake crotalus durissus terrificus. it is a 26.5 kda alphabeta heterodimer consisting of two homologous disulfide-linked chains. the crystals belong to space group i4, with unit-cell parameters a = b = 131.61, c = 121.85 a, and diffraction data were collected to 2.7 a. the structure was solved by molecular replacement and the asymmetric unit contains two alphabeta heterodimer ... | 2003 | 14501123 |
| molecular cloning of a gamma-phospholipase a2 inhibitor from lachesis muta muta (the bushmaster snake). | several endogenous phospholipase a(2) inhibitors (plis) have been purified from the blood plasma of a number of snake species and are classified into three classes (alpha, beta and gamma) according to their structure and specificity. in the present study we have cloned transcripts of a protein homologous to cnf, a gammapli present in crotalus durissus terrificus plasma, that is encoded in the liver of lachesis muta muta (the bushmaster snake), a species evolutionarily related to crotalus. the cd ... | 2003 | 12782092 |
| crotoxin acceptor protein isolated from torpedo electric organ: binding properties to crotoxin by surface plasmon resonance. | crotoxin, a potent neurotoxin from the south american rattlesnake crotalus durissus terrificus, is a heterodimeric phospholipase a(2) (ec 3.1.1.4), which blocks the release of acetylcholine from peripheral neurons. we previously have suggested the existence of a 48 kda crotoxin-binding protein in the presynaptic membranes of the electric organ of torpedo marmorata. here, we report the purification and characterization of this protein that we called the crotoxin acceptor protein from torpedo (cap ... | 2003 | 12657321 |
| [snake envenomation in french guiana]. | french guiana is a french overseas department in south america. ninety-five percent of the territory is a tropical rainforest. its rich fauna includes seven families of snakes but only 3 are potentially venomous. less than 12% of species and, depending on biotope, 10 to 30% of specimens collected are dangerous for humans. the annual incidence of snakebite is less than 50 bites per 100,000 inhabitants overall but increases to 600 per 100,000 for persons active in the rainforest where the risk is ... | 2002 | 12192717 |
| a taxonomic bibliography of the south american snakes of the crotalus durissus complex (serpentes, viperidae). | a survey is made of the taxonomic literature on south american rattlesnakes (genus crotalus, family viperidae). two main areas are emphasized: the attribution of the names proposed in the eighteenth century by linnaeus and laurenti, and the current scheme of division in subspecies. the attribution of names is examined based on the original descriptions and on relevant previous and contemporary literature. the presently adopted scheme, proposed by klauber (1941, 1972) is found not entirely satisf ... | 2002 | 11960177 |
| a proposed 3d structure for crotamine based on homology building, molecular simulations and circular dichroism. | crotamine, isolated from the venom of the south american rattlesnake crotalus durissus terrificus is a strongly basic 42-amino acid polypeptide belonging to the small basic myotoxin family. as no tridimensional structure is available for this myotoxin subfamily, despite its important pharmacological interest, we propose in this paper a theoretical 3d model for crotamine. starting from a homology modelling procedure, followed by intensive molecular dynamics (md) simulations in water and complemen ... | 2002 | 11887801 |
| effects of (60)co gamma radiation on crotamine. | ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. this has been employed to attenuate animal toxins. crotamine is a strongly basic polypeptide (pi 10.3) from crotalus durissus terrificus venom composed of 42 amino acid residues. it induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. the objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated c ... | 2001 | 11717705 |
| tolerance to the antinociceptive effect of crotalus durissus terrificus snake venom in mice is mediated by pharmacodynamic mechanisms. | crotalus durissus terrificus venom exerts central and peripheral antinociceptive effect mediated by opioid receptors. the present work investigated the tolerance to the antinociceptive effect of the venom and characterised the mechanisms involved in this phenomenon. the hot plate test, applied in mice, was used for pain threshold determination. the venom (200 microg/kg) was administered by oral route, daily, for 14 days, and the nociceptive test was applied before and on days 1, 7 and 14 of the ... | 2001 | 11384730 |
| enzymatic characterization of a novel phospholipase a2 from crotalus durissus cascavella rattlesnake (maracambóia) venom. | the pla2 and crotapotin subunits of crotoxin from crotalus durissus cascavella venom were purified by a combination of high-performance liquid chromatography (hplc) molecular exclusion (protein pack 300sw column) and reverse-phase hplc (rp-hplc). tricine sds-page showed that the pla2 and crotapotins migrated as single bands with estimated molecular masses of 15 and 9 kda, respectively. the amino acid composition of the pla2 showed the presence of 14 half-cysteines and a high content of basic res ... | 2000 | 11307952 |
| systemic skeletal muscle necrosis induced by crotoxin. | systemic skeletal muscle necrosis induced by crotoxin, the major component of the venom of crotalus durissus terrificus, was investigated. mice received an intramuscular injection of crotoxin (0.35mg/kg body weight) into the right tibialis anterior (ta) muscles, which were evaluated 3h, 24h and 3 days later. control mice were injected with saline. right and left tas, gastrocnemius, soleus and right masseter and longissimus dorsi were removed and frozen. histological sections were stained with to ... | 2001 | 11306124 |
| effect of membrane composition and of co-encapsulation of immunostimulants in a liposome-entrapped crotoxin. | crotoxin isolated from the venom of crotalus durissus terrificus (south american rattlesnake) was incorporated into liposomes by the dehydration-rehydration vesicle method using different membrane compositions and the co-encapsulation of immunostimulants. crotoxin was also encapsulated into liposomes formed from a non-phospholipid amphiphile, a mixture of polyoxyethylene 2-cetyl ether, dicetyl phosphate and cholesterol. the preparations were characterized in relation to stability, toxicity and t ... | 2001 | 11277856 |
| enzymatic characterization of a novel phospholipase a2 from crotalus durissus cascavella rattlesnake (maracambóia) venom. | the pla2 and crotapotin subunits of crotoxin from crotalus durissus cascavella venom were purified by a combination of hplc molecular exclusion (protein pack 300sw column) and reverse-phase hplc (rp-hplc). tricine sds-page showed that the pla2 and crotapotins migrated as single bands with estimated molecular masses of 15 and 9 kda, respectively. the amino acid composition of the pla2 showed the presence of 14 half-cysteines and a high content of basic residues (lys, arg, his), whereas the crotap ... | 2000 | 11233174 |
| sexual dimorphism in the hypothalamo-pituitary-adrenal (hpa) axis and tnfalpha responses to phospholipase a2-related neurotoxin (from crotalus durissus terrifcus) challenge. | neuroendocrine-immune interactions are vital for the individual's survival in certain physiopathological conditions such as sepsis and tissular injury. it is known that several snake venoms (sv) are potent neurotoxic compounds and that their main component is a specific phospholipase type 2 (pla2). it has been recently described that the venom from crotalus durissus terrificus (sv) possesses a cytotoxic effect in different in vitro and in vivo animal models. in the present study we investigated ... | 2016 | 11005268 |
| red blood cells from the south american rattlesnake (crotalus durissus terrificus) regulate volume incompletely following osmotic shrinkage and swelling in vitro. | the ability of rattlesnake (crotalus durissus terrificus) red blood cells to volume regulate in vitro has been investigated. blood was drawn through a catheter inserted in the dorsal aorta and equilibrated to gas mixtures of different composition. cells shrunken osmotically by increasing the extracellular osmolarity from approximately 291 mosm l(-1) (n=3) to approximately 632 mosm l(-1) (calculated) only partially regulated their volume back towards the original volume either at ph 7.51+/-0.05 ( ... | 2000 | 10996817 |
| role of the recombinant non-integrin platelet collagen receptor p65 on platelet activation induced by convulxin. | convulxin (cvx) isolated from crotalus durissus terrificus venom selectively binds with a high affinity to platelets and induces platelet aggregation by a mechanism that resembles that induced by collagen. taking advantage that p65 has been recently cloned and expressed as a recombinant soluble protein (rec-p65), we examined the role of this non-integrin collagen receptor in platelet activation induced by cvx. rec-p65 blocked platelet adhesion to collagen-coated surfaces and inhibited platelet a ... | 2000 | 10772928 |