SNAKE BITES VENOM AND ANTI-VENOM
Snake venom is modified saliva and is produced by modified saliva glands. Venoms are rich in hydrolithic enzymes, a complex mix of polypeptides, nucleases, peptidases, etc., which help digest the snake's prey. Some of them also enhance or contribute to the toxic effect of the venom. As early as 1949 it was shown that an enzyme from the Bothrops species produces a vasodilation resulting from the production of a hypotensor neuropeptide, bradykinin. This had important consequences for man leading to drugs for the control of blood pressure. The proteins that can kill or immobilize prey vary and differ in their effect and the percentages in which they are present in venom. | Some toxins and their effects | |Class |Examples |Action | |α-Neiurotoxins |a-Bungarotoxin, a-toxin, erabutoxin, cobrotoxin|Blocks neuromuscular transmission by linking, like | | | |curare, onto the cholinergic receptor found on the | | | |skeletal muscle fibers | |-Toxins |κ-Toxin |Blocks some of the central nervous system's cholinergic | | | |receptors | |β-Neurotoxins |Notexin, ammodytoxin, β-bungarotoxin, crotoxin,|Blocks neuromuscular transmission by keeping nerve ends | | |taipoxin |from liberating acetylcholine. Possible interaction with | | | |potassium canal sensitive to voltage. | |Dendrotoxins |Dendrotoxin, toxins І and κ |Increases amount of acetylcholine liberated by nerve | | | |ends. Possible interaction with potassium canal sensitive| | | |to voltage. | |Cardiotoxins |Υ-Toxin, cariotoxin, cytotoxin |Disturbs the plasma membranes of some cells like cardiac | | | |fibers and results to lysis. Leads to cardiac arrest. | |Sarafotoxins |Sarafotoxins a, b and c |Powerful vasoconstrictors affecting the cardiac system as| | | |a whole leading to cardiac arrest. | |Mytotoxins |Myotoxin-a1, crotamine |Leads to muscular degeneration by interacting with a | | | |sodium canal dependent on voltage | | |Phospholipase A2 |Leads to muscular degeneration | |Hemorrgines |Mucrotoxin A, hemorragic toxins a,b,c, HT1 and|Leads to very serious hemorrhages by altering the vessel | | |HT2 |walls. |
The protein-like nature of snake venom was established by Napoleon Bonaparte's brother, Lucien in 1843. Proteins constitute the major portion of venom's dry...
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