Venom components

Major Venom Components Cause Paralysis of Prey... 

From this brief review of marine vertebrate venoms, it is obvious that very few biochemical investigations have been done. The technology to study marine vertebrate venom components is available. There are simply not enough scientists interested enough to enter the field. The first task is to isolate the toxic principles and identify the amino acid sequences. Pharmacological investigation should be done on the purified toxic principle and not on the crude venom, which is a mixture of many proteins and nonproteins. 

Chacur M, Gutierrez JM, Milligan ED, et al. Snake venom components enhance pain upon subcutaneous injection an initial examination of spinal cord mediators. Pain 2004 111 65-76. 

The venom of the fire ant, Solenopsis punctaticeps, contains several 2,5-dialkyl-pyrrolidines and -pyrrolines their structures have been settled by combined g.c-m.s., and confirmed by syntheses employing the Hofmann-Loffler reaction on the corresponding primary amines.7 A new synthesis of 2,5-dialkyl-pyrrolidines via lithiated iV-nitrosopyrrolidine and two stages of alkylation, followed by removal of the nitroso-group, should be applicable to the synthesis of the venom components. The major products are trans in stereochemistry.8... 

Venom components differ among the multitude of scorpion species and thus venom distributes to different tissue sites. 

Scorpion venom may reach systemic circulation through lymphatic transport following a sting. Of those scorpions located in the United States, Centruroides exilicauda, found in southeastern California, Arizona, Nevada, southern Utah, and southwestern New Mexico, is an example of a scorpion that can produce significant systemic toxicity following envenomation. Onset of systemic symptoms typically occurs within 4h of the sting. The metabolism of venom components is not well understood. Tissue distribution of venom is complex. 

Scorpion venom is composed of many different fractions that can vary among the different scorpion species. These venom fractions act at different tissue receptor sites. Local tissue reaction is a result of the inflammatory response to the injected foreign proteins and enzymes making up the venom. The venom of Centruroides species contains several different neurotoxins. These toxins block the transmission of nerve impulses in the central nervous system and in muscles by blocking the transport of ions through sodium and potassium channels at the cellular level. Other venom components may decrease the heart rate by causing the release of acetylcholine. 

Systemic absorption of venom is dependent on lymphatic transport following subcutaneous envenomation. The onset of local symptoms such as swelling and ecchymosis occurs within several hours. Cardiovascular, neurological, or hematological compromise varies in onset but may occur within 10-15 min following intravenous or intraarterial envenomation. The metabolism of venom components is not well understood. It is likely that venom components are inactivated by enzymes within tissues where the venom is ultimately distributed. The distribution of... 

Snake venoms are complex mixtures of several different components or fractions that can vary considerably within Crotalinae members. A complete review of venom components is beyond the scope of this review. Depending on the content of the venom, multiple organ systems may be affected. Historically, Crotalinae venom was classified as neurotoxic, hemotoxic, cardiotoxic, or myotoxic, depending on the species of snake involved in the envenomation. This oversimplifies the complex nature of Crotalinae venom. Clinically, a patient may develop such multisystem disorders as platelet destruction, internal bleeding, hypotension, paresthesias, and rhabdomyolysis. 

Elapidae venom is composed of different components that vary among species. The venom of North American species contains fractions that are primarily neurotoxic. The venom results in a bulbar-type cranial nerve paralysis. In contrast to Crotalinae species, venom from North American elapids lacks most of the enzymes and spreading factors that cause local tissue destruction. Elapids from countries other than the United States can contain venom components different than that of North American coral snakes. 

In humans, the specific disposition of venom is not well understood. The local distribution of venom is enhanced by the presence of hyaluronidase and other spreading factors found in the venom. Systemic absorption of venom components is likely dependent on lymphatic transport. The onset of local symptoms such as redness and pain may develop within a few hours of the bite. 

Brown Recluse spider venom contains many diverse protein fractions including spreading factors and enzymes such as hyaluronidase, collagenase, protease, phospholipase, and others. These venom components cause coagulation of blood and, ultimately, the occlusion of small blood vessels at the bite site. This leads to local skin and tissue necrosis due to ischemia. Hemolysis of red blood cells may also occur. The normal inflammatory processes that follow, such as edema and hemorrhage, contribute to the tissue damage caused by the venom. 

New 2,6-dialkylated piperidines (207-210) have been isolated as cis/trans mixtures from the ant venom of Monomorium delagoense [487], Their structures were determined using MS, catalytic hydrogenation to the hydrocarbons, and methoxymercuration-demercuration followed by MS analysis. The structures of 207-209 were confirmed by synthesis of the cis/trans mixtures from the corresponding dialkyl pyridines. The major venom component, cis/trans 207, displayed potent insecticial activity against Reticulitermes worker termites (LD50 = 150 pg/g termite). In addition, 207 was a potent repellent for the ants Pheidole and Iridomyrmex [487],... 

Simple pyridine, pyrazine, and pyrrolo derivatives have been described from many different types of arthropods. Nicotine (177), nicotinamide, nicotinic acid, 2-pyrrolidone, N-methylpyrrolididone (178), 8-hydroxyquinoline (179), and 2-isobutyl-3-methoxypyrazine (180) have been detected in the defensive secretion and blood of larvae of the moth Lymantria dispar The nicotine isomer anabasine (181) and its congener anabaseine (182) have been identified as venom components in several ant species,whereas... 

I. Mechanism of toxicity. Snake venoms are complex mixtures of 50 or more components that function to immobilize, kill, and predigest prey. In human victims, these substances produce local digestive effects on tissues as well as hemotoxic, neurotoxic, and other systemic effects. The relative predominance of digestive, hemotoxic, or neurotoxic venom components depends on the species of the snake and geographic variables. 

Hydrogen cyanide formation may contribute to the toxicity of snake venom, owing to the high levels of L-amino acid oxidase in some snake venoms. This enzyme is harmless on injection, but the tissue destruction caused by other venom components probably provides the required substrate and cofactor for HCN production. Cyanide inhibits ion... 

CjoHiaNj, Mr 162.23, D. 1.046, mp. 9°C, bp. 270-272 C, [a]p -82.2°. A. is a tobacco alkaloid from many Nicotiana species (Solanaceae). Its name is derived from the plant Anabasis aphylla (Chenopo-diaceae) in which it occurs as the main alkaloid in addition it is found in several other plants from various families (including Fabaceae, Berberidaceae) and in marine ribbon worms it has also been identified as a venom component in north American ants. It exhibits toxicity similar to that of nicotine and is used as an insecticide. 

From this review we see that symbiotic viruses from the braconids and the ichneumonids have some differences in their physical structures and their apparent interaction with the host. Some variations noted in the action of these viruses may eventually be correlated with differences in viral structures and the interaction of the viruses with venom components. Certain host tissues may be susceptible to one virus-type and refractive to the other virus-type. It is possible that ichneumonids, which are commonly known as tissue feeders, contain symbiotic viruses that have a more prominent effect on the endocrine system of the host, thereby preserving the host tissue. In comparison, braconids, which... 

Abstract - The crucial details for the interpretation of spatial structures and intermolecular interactions of peptides and proteins could be revealed by proper combination of physical and chemical techniques. The paper presents the results of the combined approach for the evaluation of the conformation in solution of honey-bee venom component apamin (18 membered polypeptide), of three dimensional structure of Central Asian cobra neurotoxin II (61 amino acid residues), and of the topography of its binding site with acetylcholine receptor Torpedo Marmorata. 

We initially sought to explain the biochemical basis of venom-induced insect paralysis by spider venom components. Using an electrophysiological assay for synaptic transmission, we deflned three classes of ion channel specific toxins, the a-, p- and co-agatoxins from Agelenopsis aperta venom. Two different types of co-agatoxins (Types I and II) were found to block insect presynaptic calcium channels. 

Figure 2. Schematic diagram the electrophysiological assay used to test for biological activity of spider venom components. Lx>ngitudinal ventrolateral muscles of Musca domestica were impaled with an intracellular microelectrode, which recorded excitatory junctional potentials (EJP) in response to nerve stimulation or ionophoretic junctional potentials (IP) in response to glutamate application by ionophoresis.

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