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At least 19 recordsLinked to original sources

PubMed2026

Antivenomic and Proteomic Assessment of Inter- and Intrapopulation Venom Variations in Nikolsky's Adder Vipera nikolskii: Comparison to Common Adder Vipera berus.

Snake venom variation has important clinical implications, yet individual-level venomics remains limited. We investigated inter- and intrapopulation variability in forest-steppe adder Vipera nikolskii and its recognition by commercial V. berus antivenom using proteomic and immunological approaches. Venoms from 12 individual V. nikolskii specimens representing two geographically distinct populations (BG and KM), together with three pooled V. nikolskii and one pooled V. berus samples were analyzed by LC-MS/MS, ELISA, Western blot, and pull-down assays. Multivariate analysis revealed relative homogeneity in BG and pronounced heterogeneity in KM venoms. Area-based proteomics revealed V. berus venom enrichment in PLA2 (34.6%), SVMP (14.6%), and CRiSP (15.6%), whereas V. nikolskii venoms were more variable. Pooled V. nikolskii venoms showed SVMP abundance (35.2-41.1%), contrasting with lower levels in individual samples. Antivenom binding was stronger for V. berus but weaker and more variable across individual and pooled V. nikolskii samples. Antivenom targeted PLA2/VEGF, CRiSP (only in V. berus), and Kunitz-type proteins. In vivo neutralization assay demonstrated strong protection against V. berus but not V. nikolskii venom. These findings reveal substantial compositional and antigenic variability in V. nikolskii venoms, highlight discrepancies between pooled and individual ones, and underscore the need for region-specific and functionally validated antivenom evaluation.

Animals↗

PubMed1977

The neutralization mechanism of Vipera palaestinae neurotoxin by a purified factor from homologous serum.

The serum of Vipera palaestinae contains two separate factors which neutralize the hemorrhagic and the neurotoxic activities of its venom. The purified antineurotoxic factor shows one major band in disc electrophoresis and an 800-fold increase in specific activity. Its molecular weight is approximately 56 000 and the isoelectric point is 4.0. These data, together with the failure to form precipitin lines in immuno-diffusion tests, suggest that the antineurotoxic factor of Vipera palaestinae serum is probably an albumin-like or alpha-globulin fraction rather than an immunoglobulin fraction. In vivo experiments show that the neutralizing protein does not protect or block the neurotoxin target sites. When the neurotoxic fraction is injected into mice intravenously at different intervals following injection of the snake serum, the neutralizing activity decreases with time. Experiments carried out in vitro show that the antineurotoxic factor is inactivated upon heating at 95 degrees C for 10 min but resists boiling when mixed with the neurotoxic component, suggesting the formation of a thermostable complex between the two components. This assumed complex dissociates at pH 2.5 and the neurotoxic activity reappears. Further investigation of the reaction with 131I-labeled neurotoxin and neurotoxin components shows that a stable complex is formed between the neutralizing protein and one of the synergistic components of the neurotoxic fraction.

Animals↗

PubMed1978

Asynchrony in the synthesis of secretory proteins in the venom gland of the snake Vipera palaestinae.

1. Venom of Vipera palastinae was subjected to isoelectrofocusing on polyacrylamide gel. The protein separation profiles were similar for different venom samples; more than 25 protein bands with a wide range of pI values could be demonstrated by this technique. 2. Labelled venom was obtained 8h after an intracardial injection of [3H]leucine. The relative radioactivities of four out of 12 main protein bands were significantly different in the venom synthesized during the 2nd day of the venom regeneration cycle as compared with the venom of the 4th day. The comparison was made in venom samples obtained from the two glands of the same snake at two different secretory stages. 3. It is concluded that the asynchronous synthesis of exportable proteins after the initiation of a new venom regeneration cycle is responsible for the non-parallel secretion of some venom proteins by the venom gland of Vipera palaestinae during the first few days after milking.

Animals↗

PubMed2026

First insights into the role of evolutionary history in shaping venom composition of Vipera ammodytes.

Understanding intraspecific venom variation requires distinguishing the contributions of neutral population history from natural selection. This study aims to determine whether venom variation in Vipera ammodytes species complex is structured across eight phylogenetic groups. Despite a complex evolutionary history, venom composition did not differ among phylogenetic groups within the analytical framework used, suggesting that shared ancestry alone does not explain venom variation. Whether local adaptation to environmental conditions explains the observed variation remains an open question for future studies.

Animals↗

PubMed1976

A phospholipase A2 with anticoagulant activity. I. Isolation from Vipera berus venom and properties.

An anticoagulant protein has been isolated by DEAE cellulose chromatography and gel filtration from the venom of the Vipera berus orientale (Eastern Europe). Purification has been completed by elution on carboxymethyl cellulose with continuous gradient at constant pH. The inhibitor of coagulation was separated from the other venom enzymes, e.g. procoagulant, fibrinogenolytic, aminoesterase and amino acid oxidase activities. It was also separated from other phospholipase components which were not related to the anticoagulant property. The inhibitor appeared as a simgle polypeptidic chain protein, formed by 119 amino acid residues, with a molecular weight of 13400 and an isoelectric point of 9.2. At low saline molarity, a monomer-trimer transition of this protein was observed. Both forms had the same amino acid composition. There were six disulfide bridges without free SH groups per phospholipase molecule. Deprived of any proteolytic activity, the clotting inhibitor displayed a high phospholipase activity in the presence of calcium. Activity did no appear with EDTA buffer deprived of cation. Finely dispersed micellar suspensions were found suitable for obtaining the highest phospholipase activity. High sodium cholate concentration or methanol/chloroform/ether solvent were effective without loss of enzymatic activity. As characteristis of phospholipase A2 (EC 3.1.1.4), the degradation products identified on thin-layer chromatography induced hemolysis of human erythrocytes. The apparent Km value 1.25 - 10(-3) M was determined on phosphatidylcholine isolated from ovolecithin. This purified berus inhibitor would be of value for investigating the involvement of phospholipids in the clotting mechanism.

Amino Acids↗

PubMed1976

Effectiveness of Zagreb antivenom against envenoming by the adder, Vipera berus.

Rhesus monkeys injected subcutaneously with 2, 3, or 4 mg Vipera berus venom per kg body-weight all died in shock. With 1 mg/kg the monkey had severe systemic and local effects taking 12 days to resolve. Five monkeys each recieved 4 mg/kg (a triple-lethal dose) and Zagreb antivenom was injected intravenously 1-4 hours after venom injection. The contents of 2 ampoules (10-8 ml) up to 3 hours later saved the monkeys; at 4 hours later the monkey died. But when the antivenom dose was raised to 16-2 ml 4 hours after venom, it saved the monkey. In addition to saving life, the antivenom greatly reduced the local venom effects. It is suggested that the results justify giving Zagreb antivenom to patients with severe adder-bite poisoning; and it should also be considered in adults to minimise morbidity from local effects.

Adult↗

PubMed1978

Intracellular transport of proteins in active and resting secretory cells of the venom gland of Vipera palaestinae.

The intracellular transport of venom proteins has been studied in active and resting venom glands of the snake Vipera palaestinae by electron microscope radioautography after an intra-arterial injection of [3H]leucine. In the active gland, most of the label is initially (10 min) found over the RER. By 30 min, the relative grain density of the Golgi complex reaches its maximum, with concomitant increase in the labeling of the condensing vacuoles. Later on, a steep increase in radioactivity of the secretory granules is observed. At 3 h, these granules, which comprise about 2% of the cell volume, contain 22% of the total grains. At the following hour, their labeling declines and at the same time the radioactivity of the secreted venom is increased. It is concluded that, in the active cell, venom proteins are transported via the Golgi apparatus into membrane-bounded granules which are the immediate source of the secreted venom. An alternative pathway, which involves the RER cisternae as a storage compartment, seems unlikely, since incorporated label does not accumulate in this compartment after prolonged postpulse intervals. The route of intracellular transport of proteins in the resting glands is similar to that of the active ones, but the rate of synthesis and transport is much slower. The present results and earlier data, thus, show that the increase in the rate of secretion after initiation of a new venom regeneration cycle is the result of accelerated rates of both synthesis and transport.

Animals↗

PubMed1975

Accumulation of some secretory enzymes in venom glands of Vipera palaestinae.

Secretion of venom in the venom glands of Vipera palaestinae was studied by measuring the protein content and enzymatic activities of L-amino acid oxidase (LAO), phosphodiesterase (PDE), and benzoylarginine ethyl esterase (BAEE). These were tested in the accumulating venom and gland homogenates at 0, 2, 3, 4,6, and 15 days after an intitial emptying of the venom glands by milking. Changes in the total activities of the enzymes and in the protein concentration were found in the venom samples, but not in the homogenates, at the different intervals after milking. In the venom the total activities of LAO, PDE, and BAEE were higher the longer the time intervals from the initial milking. When the data were fit by a straight line, the fluctuations from the line were of opposite signs for LAO and PDE at the 3- and the 4-day intervals. There were no significant correlations between the specific activities or between the changes in the specific activities of any two of the enzymes at any time interval. It is concluded that each of the enzymes is secreted at a rate independent of the other two; this pattern of secretion can best be described as nonparallel.

Amino Acid Oxidoreductases↗

PubMedDate not supplied

[Populational differences in venom composition in the snake Vipera lebetina turanica].

Studies have been made on the toxicity, enzymic activity and fractional composition (polyacrylamide gel electrophoresis) of the venom obtained from various populations of the snake Vipera lebetina turanica. Animals were captured in different regions of the Mid-Asian part of the USSR. Electrophoretic studies reveal differences in fractional composition, mobility and density of proteins in the venoms studied. However, no significant variations were found in the enzymic activity and toxicity of the venoms.

Animals↗

PubMedDate not supplied

Seasonal changes of the structure and function of prolactin cells in the pituitary gland of Vipera berus (L.).

A selective staining by the indirect immunofluorescence method has been used for prolactin cells (PRL-cells) in the pituitary gland of Vipera berus (L.). The PRL-cells showed significant seasonal changes as judged by their morphological features, their number and localization in the pars distails. In the functional cycle of the cells 4 periods could be distinguished: 1 -- spring (March --May), when the release of the hormone as well as its increasing accumulation were observed; 2 -- early summer (June -- July), when the accumulation of the hormone in the gland reached the maximum and prevailed the release; 3 -- late summer (August), when was observed a rapid PRL release with a simultaneous exhaustion of cell reserves: 4 -- autumn (September), was characterized by small PRL content in the cells and its inconsiderable release.

Animals↗

PubMedDate not supplied

[An enzootic with pseudo-tumoral manifestations in Vipera lebetina in captivity].

The authors report the clinical and epizootic evolution of an epizooty, characterized by pseudo-tumours, observed on some vipers (Vipera lebetina) maintained in captivity at the "institut Pasteur de Tunis". The disease was characterized by 2.3 cm size nodules, scattered under the skin or into splanchnic cavities. These ones, spherical and well capsuled, were formed by a mass of clear rounded cells (histiocytes or monocytes), the necrotic central area of which contained innumerable bacteria. Several reviewed works show that this appearance of chronic abcess is a common and univocal reaction to various pathogenic factors, such as bacteria and parasites. As to etiology, the authors have doubt about the pathological role of the germs which they have identified (Salmonella and other anterobacteria) because these latter belong to the normal microbial flora of snakes and are, in the present case, probably occasional infective agents only.

Animals↗

PubMed1977