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PubMed1991

Contractile activity of Trimeresurus flavoviridis phospholipase A2 on guinea pig ileum and artery.

Trimeresurus flavoviridis phospholipase A2 (PLA2) induced strong contractions of the smooth muscles of guinea pig ileum and artery in a concentration-dependent manner (10(-10)-10(-6) M). When the same dose of PLA2 was administered in repetition to the ileal preparation, the contraction diminished progressively and was no longer recovered even by consecutive washings. The enzymatically inactive derivative of PLA2, in which His-47 was p-bromophenacylated, was unable to elicit contraction. Also, no activity was observed when the Ca(2+)-free medium was used. The contraction induced by PLA2 was inhibited completely by 1.0 x 10(-6) M indomethacin, but not by nordihydroguaiaretic acid. These results imply that the PLA2-induced contraction is due essentially to the hydrolytic action of the enzyme against phospholipid membranes to liberate arachidonic acid that is then converted to pharmacologically active prostaglandins. In guinea pig artery, PLA2 caused both contraction and relaxation.

Animals↗
PubMed1991

Pharmacological actions of chemically-modified phospholipase A2 from the venom of Trimeresurus flavoviridis on the smooth muscle of the rat stomach fundus.

The pharmacological activities of Trimeresurus flavoviridis phospholipase A2 (PLA2) and their chemically-modified PLA2 were characterized by measuring the contraction of rat stomach fundus strips. The native PLA2 produced a contraction of rat fundus strips. The alpha-amino-modified enzyme induced an almost identical contraction of the fundus with that of the native enzyme, whereas His-modified and Lys-modified enzymes induced a markedly decreased contraction as compared with the native enzyme. These results demonstrate that lysine and histidine residues but not the alpha-amino group in the PLA2 molecule are essential for contractile activity of the stomach fundus.

Animals↗
PubMed1991

The primary structure of coagulation factor IX/factor X-binding protein isolated from the venom of Trimeresurus flavoviridis. Homology with asialoglycoprotein receptors, proteoglycan core protein, tetranectin, and lymphocyte Fc epsilon receptor for immunoglobulin E.

An anticoagulant protein, factor IX/factor X-binding protein (IX/X-bp), isolated from the venom of Trimeresurus flavoviridis, binds with factor IX and factor X in the presence of Ca2+ with a 1 to 1 stoichiometry (Atoda, H., and Morita, T. (1989) J. Biochem. (Tokyo) 106, 808-813). Analysis of S-pyridylethylated IX/X-bp by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a 16.0-kDa band (designated the A chain) and a 15.5-kDa band (designated the B chain). These two chains were separated by reversed-phase high performance liquid chromatography, and their complete amino acid sequences were determined by sequencing of the peptides obtained after digestion with lysyl endopeptidase, chymotrypsin, and V8 protease from Staphylococcus aureus and after chemical cleavage with cyanogen bromide. The A chain had an amino-terminal sequence of Asp-Cys-Leu-Ser-Gly- and consisted of 129 residues with Mr 14,830. The B chain has an amino-terminal sequence of Asp-Cys-Pro-Ser-Asp- and consists of 123 residues of Mr 14,440. There was 47% identity between the A and the B chain. The sequence of IX/X-bp showed 25-37% identity with that of the C-type carbohydrate recognition domain-like structure of acorn barnacle lectin, human and rat asialoglycoprotein receptors, the human lymphocyte Fc epsilon receptor for immunoglobulin E, proteoglycan core protein, pancreatic stone protein, and tetranectin. The sequences of the first 18 amino acid residues of both the A and B chains were also, to a certain extent, homologous to the partial amino acid sequence of the b subunit of factor XIII, a member of the beta 2-glycoprotein I-like family. In this region, some similarity with the amino-terminal amino acid sequence of botrocetin was also observed.

Aggrecans↗
PubMed1990

Mouse paw oedema induced by Habu snake (Trimeresurus flavoviridis) venom: inhibition by morphine, naloxone and methylnaloxone alone or in combinations.

The oedema produced in the mouse by intraplantar injection of the venom of Trimeresurus flavoviridis was inhibited by morphine (Mo) and by naloxone (Nx); the action of Mo increased with the dose, whereas that of Nx first progressed and thereafter regressed with the dose; very small doses of Nx antagonized Mo. Methylnaloxone (MeNx), a quaternary ammonium derivative of Nx was much less effective than Nx by the subcutaneous route but almost as effective by the intraplantar route. Peripheral opioidergic receptors are thus likely to be involved. Very high doses of Mo acted an synergistically with an optimal dose of EDTA or zymosan; complex interactions occurred between lower doses of Mo or Nx and EDTA or zymosan.

Animals↗
PubMed1991

Amino acid sequences of the two subunits of a phospholipase A2 inhibitor from the blood plasma of Trimeresurus flavoviridis. Sequence homologies with pulmonary surfactant apoprotein and animal lectins.

Phospholipase A2 inhibitor (PLI), purified from the blood plasma of the Habu snake (Trimeresurus flavoviridis), was separated into two distinct subunits, PLI-A and PLI-B. These subunits were shown to be glycoproteins with molecular weights of around 21,000-22,000. When they were deglycosylated chemically with trifluoromethanesulfonic acid, the molecular weights were found to be 17,000. Their amino acid sequences were determined by alignment of peptides obtained by lysyl endopeptidase digestion and Staphylococcus aureus V8 protease digestion. PLI-A and PLI-B were each composed of 147 amino acid residues with one residue, Asn103, being for N-linked glycosylation, and the molecular weights of their protein portions were calculated to be 16,368 and 16,408, respectively. Each subunit contained four cysteine residues, all of which exist in disulfide linkages (Cys64-Cys141 and Cys119-Cys133). The sequences of PLI-A and PLI-B showed 89.9% homology to each other. When the sequences were compared with those of lipocortins, no significant homologies were detected. But the sequences were significantly homologous to those of COOH-terminal carbohydrate recognition portions of pulmonary surfactant apoprotein and animal lectins.

Amino Acid Sequence↗
PubMed1990

Bites by the white-lipped pit viper (Trimeresurus albolabris) and other species in Hong Kong. A survey of 4 years' experience at the Prince of Wales Hospital.

The case records of 242 snake bite victims admitted to the Prince of Wales Hospital in Hong Kong between September 1984 and October 1988 were studied retrospectively. When the snake was identified, the White-lipped pit viper (Trimeresurus albolabris) was by far the commonest species involved. In addition to local oedema and inflammation, evidence of a significant blood clotting disturbance was present in at least 10% of cases, defibrination and thrombocytopenia being the commonest findings. Since such abnormality was not always sought the true figure is likely to be higher. Three fatalities occurred, one of which was secondary to a probable White-lipped pit viper bite, one to a bite by Chinese cobra and one to a bite by Russell's viper.

Adult↗
PubMed1990

The complete amino acid sequence of the high molecular mass hemorrhagic protein HR1B isolated from the venom of Trimeresurus flavoviridis.

Hemorrhage is a common occurrence in a victim bitten by crotalid and viperid snakes, and hemorrhagic components in these various venoms have been isolated and characterized. Previously, we have shown that a low molecular weight hemorrhagic protein (HR2a, 202 amino acid residues) isolated from the venom of Trimeresurus flavoviridis is a member of a new subfamily of metalloproteinases. We now report the complete amino acid sequence of a high molecular mass hemorrhagic protein isolated from the same venom. This protein, HR1B, is a mosaic protein composed of 416 residues containing four asparagine-linked oligosaccharide chains. The amino-terminal half (residues 1-203) of HR1B contains a metalloproteinase domain, the sequence of which is 62% identical to that of HR2a and 52% identical to that of hemorrhagic toxin d isolated from Crotalus atrox venom. The most interesting finding is that the middle region (residues 204-300) of HR1B shows a striking similarity to disintegrins, Arg-Gly-Asp-containing platelet aggregation inhibitors, recently found in several viper venoms. Interestingly, however, this region of HR1B does not contain the Arg-Gly-Asp sequence which is known to be a putative binding site in the disintegrins for the platelet fibrinogen receptor, the glycoprotein IIb-IIIa complex. We also found that the carboxyl-terminal region (residues 213-336) of the middle part of HR1B shows 30% identity to residues 1543-1656 of von Willebrand factor and that the remaining region at the carboxyl-terminal end is unique and has a cysteine-rich sequence. These results suggest that the middle portion of HR1B, which shows structural similarities to the disintegrins and von Willebrand factor, may be important in synergistically stimulating hemorrhagic activity in the NH2-terminal metalloproteinase domain.

Amino Acid Sequence↗
PubMed1988

Antagonists of mouse paw oedema induced by Habu snake (Trimeresurus flavoviridis) venom. Inhibitions by various antagonists administered alone or in combinations.

When injected into the sole of the hind paw of mice, Habu snake (Trimeresurus flavoviridis) venom produced a prolonged oedema (72 hours). When administered alone, most of the studied drugs (mepyramine, methysergide, cyproheptadine, indomethacin, aspirin, dexamethasone and aprotinin) inhibited this oedema only partially and transiently (less than 7 hours). Some drugs however (EDTA, Biogel P4, zymosan and celluloses) were able to abolish it progressively. Combinations of some of these drugs resulted in various synergisms; in particular important and prolonged inhibitions were observed with aprotinin-dexamethasone, one of these drugs and EDTA, and especially EDTA-zymosan, which abolished totally the oedema from 2 hours after the injection of the venom to its end (72 hours). Antagonisms between components of combinations were also observed. The mechanisms of these synergisms and antagonisms are discussed. In particular, it is suggested that the blockade of the two pathways "classical" and "alternative", of the complement by EDTA and zymosan respectively might account for their important and early synergism. Antagonisms also helped in indicating some mechanisms of action.

Animals↗
PubMed1987

Light microscopic observations of the vomeronasal organ of Habu, Trimeresurus flavoviridis.

Light microscopic observations of the vomeronasal organ (VNO) (Jacobson's organ) of Habu, Trimeresurus flavoviridis, revealed that the organ was encased in the os vomeris and the vomeronasal cartilage on either side of the nasal septum. Habu VNO was divided into a dome-shaped portion mainly composed of a sensory epithelium (SE) and a hemispherical mushroom body covered with a ciliated epithelium. A narrow lumen, leading to the oral cavity via the vomeronasal duct, was made between the mushroom body and the SE. The SE consisted of a supporting cell layer facing the lumen and the underlying sensory cell layer where a large number of cells piled up in columns. Vascular plexuses were found around the neck and bottom of the columns. Along the antero posterior axis of the VNO, the height of the columns reached its maximum in the middle of the dorsal and the median parts (over 300 micron), and gradually decreased toward lateral. Each column contained undifferentiated basal cells, sensory cells and satellite cells. Sensory cells had a round nucleus and prominent lipofuscin granules. The sensory cells were arrayed in a string-like arrangement. Cells situated in the neck region of columns contained a larger amount of lipofuscin granules. Distal processes of sensory cells passed through the cytoplasmic meshwork of supporting cells and terminated as small swellings. Aggregates of heterogeneous cell populations were observed in the antero lateral region of the dome. A number of pigment cells were seen in the epineurium and the perivascular regions of the dorsal and lateral VNOs. Goblet cells were present in the lateral boundary between the dome portion and the mushroom body. Present findings clarify the complex organization of the Habu VNO, and the occurrence of the sensory columns similar to those reported in other snakes.

Animals↗
PubMed1985

[Proteolytic destruction of a hemorrhagic toxin from the venom of the habu (Trimeresurus flavoviridis)].

The major hemorrhagic principle (HR1B) in the venom of Habu (Trimeresurus flavoviridis), a crotalid, was found to be easily inactivated and hydrolyzed by a commercial protease (Nagarse). The ability of the hydrolysate to produce the toxin-neutralizing antibody has been shown to be comparable to or superior to those of two formol toxoids used as the controls, suggesting that inactivation of HR1B by the protease provides a new method for the preparation of Habu toxoid.

Animals↗
PubMed1984

Evaluation of a bait trap for Habu, the venomous snake, Trimeresurus flavoviridis.

The box trap for the venomous snake, Trimeresurus flavoviridis, 25 X 45 cm and 15 cm high, was made of a sheet of polypropylene board, and involved the use of a small rodent in a wire mesh cage as bait. The efficacy of this trap was evaluated in the field on Tokunoshima Island, one of the southern-most islands of Japan. The catch rate of the trap was expressed by the probability of snakes caught in trap-days, a product of the number of traps set and the period of set days. In one experiment, a result was successfully achieved by setting the boxes for almost 2,000 trap-days each for 2 different test materials in a limited geographical area. The one-way entrance made of flexible polyethylene sticks arranged conically allowed significantly more invasion of snakes than that of a swinging hinged door as shown by the catch rates of 12 snakes/1721 trap-days to 0/1682, respectively. Using traps with a conical entrance, the catch rate with the albino rat, Ratus norvegicus, was 6/2324 which was significantly higher than 0/2450 using rat feces as attractant. The catch rate with the field rat, Ratus rattus, at 31/2402 was significantly about 6 times higher than 5/2446 with the albino rat, whereas an albino rat was about 5 times more attractive than 2 albino mice at significantly different rates of 17/2455 and 3/2284, respectively. The box trap baited with a small rodent proved attractive to snakes and attractiveness differed with the species of bait animals.

Animals↗
PubMed1984

The electric net trap for the venomous snake, Habu, Trimeresurus flavoviridis.

The electric net trap made of 3 rows of polyethylene net fence with the high voltage electric pulse was examined in the field for capturing the venomous snake, Trimeresurus flavoviridis. The bottom of the center row of the net fence was buried in the ground and that of other two outer rows was partially free from the ground so that snakes were allowed to invade one way into the spaces at both sides of the center net. The examination using a 90 m net trap set for 116 days resulted in the capture of 44 snakes, i.e., 7 T. flavoviridis, 7 Dinodon semicarinatus and 33 Opheodrys semicarinatus, of which the latter two were nonvenomous. The result indicated that the net trap was an efficient tool for capturing snakes and in identifying the direction of snake movement. In the other studies conducted in 1982 and 1983, a 178.5 m net trap was set at a part of a 2,000 m electric net barrier, which surrounded a 12.8 ha sugar cane field and thereby prevented snake invasion. The number of venomous snakes captured by the inner net trap was remarkably reduced from 13 in 1982 to 0 in 1983, in contrast to 8 and 9, respectively, observed in the outer trap. The decrease of snake population was also observed in 100 box traps baited with a live rat set inside the enclosed area. The ratio of immature snakes captured by the net trap was significantly higher than that by the box trap.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

The electric fence for preventing invasion of Trimeresurus flavoviridis, Habu, the venomous snake.

For the purpose of preventing invasion of Trimeresurus flavoviridis, Habu, the venomous snake, the effect of an electric fence made of hollow tile blocks or polyethylene net was examined in 3 villages on Amamioshima and Tokunoshima islands in the southernmost area of Japan. The electric pulses were supplied by a pulse maker at 0.75 sec. intervals with 480 mA, 0.13 m coulombs at a load of 500 ohms and estimated peak of 8 to 10 kV. The anode from a pulse maker was connected to a stainless steel plate or a metal string woven in a vinyl rope on the fence and the cathode was grounded. The power to the pulse maker was generated by silicon solar cells, stored in a car battery and regulated by an electric eye switch to activate it at night. The necessary height of the fence to prevent Habu from slithering over the fence was experimentally determined to be 60 cm. In 3 villages, 6.75 ha were enclosed with 1000 m fence, 13.7 ha with 2100 m and 23.8 ha with 2500 m, respectively. The effect of the electric fence was remarkable as determined by the annual monitoring of the number of snakes sighted by people and the captivity rate in box traps inside the fence. The number of snakes found annually in Tean Village was 10 before construction and 5, 4, 5 after construction; 119 before construction 55, 20, 20 after construction at Tete; and 109 and 82 before construction and 15 and 11 after construction at Todoroki. The snakes were observed to aggregate outside the fence. The net barrier could be constructed at any topographical conditions with less expense. The effect was further pronounced when snakes were removed by box trap and other methods from inside the fenced area.

Animals↗
PubMed1982

Biological properties of Trimeresurus mucrosquamatus venom and its fractions.

Trimeresurus mucrosquamatus venom was separated into two principle fractions by Sephadex G-100 gel filtration. Fraction I (FI) contained the main part of lethal and hemorrhagic activities and minor part of proteolytic activity on casein. The lethal dose of FI determined by the i. v. injection was significantly smaller than that of the i. p. injection, while the result of fraction II (FII) was reversed. The venom was susceptible to heat, pH and cysteine-HCl but not to albumin, sodium glutamate, sorbitol and glycine.

Animals↗
PubMed1994

Isolation and characterization of a toxic phospholipase A2 from the venom of the Taiwan habu (Trimeresurus mucrosquamatus).

A toxic phospholipase A2 (PLA2) was isolated from Taiwan-habu-snake (Trimeresurus mucrosquamatus) venom by sequential chromatographies on CM-52, Sephadex G-75 and S-Sepharose columns. This basic PLA2 has a single polypeptide with an estimated M(r) of 15,000. The PLA2 activity was Ca(2+)-dependent and inactivated by p-bromophenacyl bromide and its specific antibody. The toxic PLA2-induced myotoxic and direct haemolytic effects as well as respiratory distress in mice with an intraperitoneal LD50 of 1.17 micrograms/g body weight. The histological examination showed it caused haemorrhage and congestion in the viscera of mice. It was also cytotoxic to myeloma cells (NS-1), baby-hamster-kidney (BHK) cells and human umbilical endothelial cells. By neutralization experiments with a specific antibody against toxic PLA2, it was found that the enzymic activity of toxic PLA2 is essential for its myotoxicity, but it is not the only factor responsible for the lethal toxicity.

Acetophenones↗
PubMed1993

Trimucytin: a collagen-like aggregating inducer isolated from Trimeresurus mucrosquamatus snake venom.

Trimucytin is a potent platelet aggregation inducer isolated from Trimeresurus mucrosquamatus snake venom. Similar to collagen, trimucytin has a run of (Gly-Pro-X) repeats at the N-terminal amino acids sequence. It induced platelet aggregation, ATP release and thromboxane formation in rabbit platelets in a concentration-dependent manner. The aggregation was not due to released ADP since it was not suppressed by creatine phosphate/creatine phosphokinase. It was not either due to thromboxane A2 formation because indomethacin and BW755C did not have any effect on the aggregation even thromboxane B2 formation was completely abolished by indomethacin. Platelet-activating factor (PAF) was not involved in the aggregation since a PAF antagonist, kadsurenone, did not affect. However, RGD-containing peptide triflavin inhibited the aggregation, but not the release of ATP, of platelets induced by trimucytin. Indomethacin, mepacrine, prostaglandin E1 and tetracaine inhibited the thromboxane B2 formation of platelets caused by collagen and trimucytin. Forskolin and sodium nitroprusside inhibited both platelet aggregation and ATP release, but not the shape change induced by trimucytin. In quin-2 loaded platelets, the rise of intracellular calcium concentration caused by trimucytin was decreased by 12-O-tetradecanoyl phorbol-13 acetate, imipramine, TMB-8 and indomethacin. In the absence of extracellular calcium, both collagen and trimucytin caused no thromboxane B2 formation, but still induced ATP release which was completely blocked by R 59022. Inositol phosphate formation in platelets was markedly enhanced by trimucytin and collagen. MAB1988, an antibody against platelet membrane glycoprotein Ia, inhibited trimucytin- and collagen-induced platelet aggregation and ATP release.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗