Mechanisms only Flashcards
(43 cards)
organophosphate pesticides (OPs)
irreversible inhibition of acetylcholinesterase (AChE) activity = anticholinesterase
ivermectin
GABA receptor agonist (depressive effects)
pyrethroid pesticides
binds voltage gated Na+ channel (excitation)
bromethalin
damages mitochondrial function (uncouples oxidative phosphorylation in CNS) -> loss of ion gradient ->fluid accumulation in myelin sheaths -> decreased nerve conduction and respiratory arrest
(CEREBRAL EDEMA)
alprazolam (xanax)
GABA receptor modulator that acts at the limbic, thalamic, and hypothalamic level of the CNS (depressive effects)
zolpidem (ambien)
inhibits neuronal excitation by binding to the benzodiazepine site of GABA receptors (depressive effects)
slaframine
muscarinic cholinergic agonist (ACh mimic) especially in exocrine glands
(SLOBBERS)
fumonism
inhibits sphingosine-N-acetyltransferase causing increased levels of sphinganine which is cytotoxic
(CORN)
strychnine
competitive antagonist at post synaptic spinal cord and medulla glycine receptors; glycine is an inhibitory neurotransmitter, therefore evokes an overstimulation (excitation)
salt
diffusion of sodium into CSF when plasma sodium levels are high leading to inhibition of glycolysis and ATP and attraction of water
(Na+ >160 mEq/L)
phenoxyacetic acid herbicides
mechanism unknown
ergot alkaloids
dopamine and serotonin receptor agonists
ionophores
increase intracellular Na+ and Ca++, leading to mitochondiral swelling and cell death, especially in muscle. remember it’s target is the mitochondiral MEMBRANE)
(heart problems)
tetanus
blocks release of GABA and glycine (both are inhibitory neurotransmitters) resulting in overstimulation of muscles resulting in stiffness
anticoagulants
inhibits vitamin K1 epoxide reductase, preventing formation of vitamin K dependent clotting factors
nitrates
nitrate->nitrite->vasodilation and ferrous iron + Hgb -> methemoglobin ->oxygen starvation of tissues
cardiac glycosides
inhibits Na+/K+ ATPase through competition with K+ for binding sites
cyanide
inhibition of cytochrome oxidase and oxidative phosphorylation
methylxanthines
competitive antagonist of adenosine receptors (causes CNS stimulation, vasoconstriction, tachycardia); prevents Ca++ reuptake, leading to increased skeletal and cardiac muscle contractility
gossypol
chelates iron and causes anemia, inhibits dehydrogenase leading to decreased energy and stress (can be cumulative as it is lipophilic)
cantharidin
inhibits protein phosphatases (dysregulates protein metabolism); mucosal irritant
(muzzle in the water)
ethylene glycol
major toxic agents of ethylene glycol are metabolites produced by the action of alcohol dehydrogenase; glycolic acid causes acidosis, glyoxilic acid thought to cause CNS signs, oxalate/oxalic acid causes renal damage and hypocalcemia
cholecalciferol/vitamin D3
causes massive increases in serum Ca++ by increasing GI absorption, decreasing renal excretion, increasing synthesis of calcium binding protein, mobilizing bone calcium
grape/raisin
unknown
