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17 Cards in this Set
- Front
- Back
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Anabaena circinalis |
Anatoxin-a Blocks neuromuscular nicotinic depolarisation Muscles Respiratory failure |
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Microcystis aeruginosa |
Microcystin Descreased phosphorylation of tubulin/other proteins in the liver --> disruption of cytoskeleton Liver failure |
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Nodularia spumigena |
Intracellular hepatoxin Cellular swelling/degeneration/necrosis Excessive peritoneal and plural fluid, haemorrhage on serosal surfaces, leucopoenia Liver failure |
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Aphanizomenon flos-aquae |
Saxitoxin Blocks Na channels at NMJ (no effect on K) |
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Aspergillus flavus |
Aflatoxin Most important Strong carcinogen Binds DNA, RNA, protein --> Inhibits transcription --> no protein synthesis Liver failure |
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Claviceps purpurea |
Ergot Alkaloid Initiate smooth muscle contraction (uterus, small arteries) --> gangrene / heat intolerance (less heat lost in periphery) Mimic dopamine in CNS Hallucinations |
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Diaporthe toxica |
Phomopsin Bind to tubulin --> inhibit assembly --> intracellular transport and mitosis hindered Myopathy: decreased Se mobilization from damaged liver Encephalopathy: hyperammonaemia Liver --> muscle / brain |
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Pithomyces chartarum |
Sporidesmin Absorbed in SI --> excreted by liver into bile --> bile canalicular membranes become inflammed Cholangitis, jaundice, retention of phylloerythrin --> photosensitisation Grows on dead leaf litter in autumn (rain+heat) -->spores carried upward by (perennial rye) grass growth Mainly problem in sheep |
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Acremonium lolii |
Lolitrems (Tremorgans/Indole akaloids) GABA and glycine antagonist Vasocontriction in cerebrum Inhibition of monoamine oxidase (serotonin activity increases) Tremors / gait abnormalities |
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Claviceps paspali |
Paspalitrems GABA and glycine antagonist Vasocontriction in cerebrum Inhibition of monoamine oxidase (serotonin activity increases) Tremors / gait abnormalities |
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Penicillium spp. |
Penitrems GABA and glycine antagonist Vasocontriction in cerebrum Inhibition of monoamine oxidase (serotonin activity increases) Tremors / gait abnormalities |
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ANNUAL RYEGRASS TOXICITY (Anguina agrostis / Clavibacter toxicus / Lolium rigidum) |
Corynetoxin Bacteria on nematodes infect seeds Inhibits transfer of pre-formed oligosaccharide to proteins --> reduced glycosylation of glycoproteins Reduces integrity BBB --> large molecules pass into brain --> CNS dysfunction Ataxia, tetany, convlusions, death Worse with stress/exercise |
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Organochlorine |
Fat soluble / stored Slow metabolism / excretion Mechanism not well understood Nervous signs = tremors, seizures, hyperthermia, blindness, death |
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Organophosphate |
Phosphates or thiophosphates Synthetic Irreversibly phosphorylate esteratic site Acetylcholinesterase inhibitor Short half life Absorbed from all surfaces / rapid Ach accumulates --> excess stimulation Progression from Parasympathetic/Sympathetic signs (vomiting, diarrhoea, salivation, lacrimation, difficulty breathing, urination, bradycardia) (muscarinic) --> NM signs (muscle tremors, twitching, paralysis) (nicotinic) --> CNS signs (depression, hyperactivity, seizures, etc) Atropine (blocks muscarinic receptors) and 2-PAM (reactivates AchE) to treat |
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Carbamate |
First found in plant Reversibly inhibit enzyme (recovers with time) Acetylcholinesterase inhibitor Short half life Absorbed from all surfaces / rapid Ach accumulates --> excess stimulation Progression from Parasympathetic/Sympathetic signs (vomiting, diarrhoea, salivation, lacrimation, difficulty breathing, urination, bradycardia) (muscarinic) Atropine might treat or exacerbate |
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Metaldehyde |
Polymer of acetaldehyde Hydrolized to acetaldehyde and polymer components by stomach acid Absorbed and hydrolyzed/oxidized in liver Exceeds liver detox capacity --> accumulation --> fragments cross BBB Decreases serotonin and GABA (anxiety, tachycardia, ataxia, convulsions, hyperthermia) |
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Methiocarb |
Reversible inhibitor cholinesterase --> Muscarinic/nicotinic overstimulation --> vomiting, diarrhoea, salivation, lacrimation, miosis, dyspnoea, micturation, bradycardia Atropine to control neural overstimulation |
