Pesticides Flashcards
Organochlorine insecticides (caged structures) NAMES
mirex
chlordecone (Kepone)
Organophosphorous insecticides
chlorpyrifos (Dursban, Lorsban), acephate, malathion, dichlorvos
toxicity occurs at the synapse
inhibition of AChE
SLUGEM/SLUG/SLUD
atropine -> ACh receptor antagonist
2-PAM -> regenerates AChE
Type II pyrethroids
CS sydrome
Salivation, tremors progress to choreoathetosis, clonic seizures
prolong Na channel openings longer -> depolarization block
Captan and folpet
broad-spectrum protectant fungicides; together with captafol, they are called chloroalkylthio fungicides,
potent eye irritants, but only mild skin irritants.
induce the development of duodenal tumors in mice,
Klaassen, Curtis D.; Watkins, John B.. Casarett & Doull’s Essentials of Toxicology, Third Edition (Lange) . McGraw-Hill Education. Kindle Edition.
Organophosphorous insecticides
NAMES
chlorpyrifos (Dursban, Lorsban)
acephate
malathion
dichlorvos
Organochlorine insecticides (Chlorinated ethane derivatives) NAMES
DDT
methoxychlor
Organochlorine insecticides (caged structures)
mirex, chlordecone (Kepone)
tremors (not seizures); hepatosplenomegaly; repro tox
Kepone (kepone shakes)
Green tobacco sickness
dermal absorption of nicotine from leaves
Activates nAChR -> nausea, vomiting, muscle weakness, rapid heart rate
Rotenone (rotenoids)
from roots of tropical leguminous plants in Asia and C and S America
Animal model for Parkinson’s (selective nigrostriatal degeneration)
inhibits mitochondrial respiratory chain (Complex 1) - by blocking electron transport at NADH–ubiquinone reductase
Klaassen, Curtis D.; Watkins, John B.. Casarett & Doull’s Essentials of Toxicology, Third Edition (Lange) . McGraw-Hill Education. Kindle Edition.
α-naphthylthiourea (ANTU)
lethal yet tasteless to rodents, while being of low toxicity to humans
main target of toxicity is the lung, where ANTU causes marked edema of the subepithelial spaces of the alveolar walls mediated by an inflammatory response.
Klaassen, Curtis D.. Casarett & Doull’s Toxicology: The Basic Science of Poisons, 9th Edition (p. 1093). McGraw-Hill Education. Kindle Edition.
Type I pyrethroids
T syndrome (tremors)
arousal, aggression, exaggerated sensitivity to stimuli
prolong Na channel openings -> repetitive firing
dithiocarbamates
fungicide
most are associated with metal moieties
chronic exposure is associated with adverse effects metabolized to a common metabolite, ethylenethiourea, that is responsible for the effects of dithiocarbamates on the thyroid, which include hypertrophy and hyperplasia of thyroid follicular cells that progress to adenomas and carcinomas.
nomenclature of many of these compounds arises from the metal cations with which they are associated; thus, there are maneb (Mn), ziram and zineb (Zn), mancozeb (Mn and Zn), and ferbam (Fe). Thiram is an example of dithiocarbamate without a metal moiety
resembles that of disulfiram, a compound used therapeutically to produce intolerance to alcohol,
Klaassen, Curtis D.. Casarett & Doull’s Toxicology: The Basic Science of Poisons, 9th Edition (p. 1090). McGraw-Hill Education. Kindle Edition.
Klaassen, Curtis D.; Watkins, John B.. Casarett & Doull’s Essentials of Toxicology, Third Edition (Lange) . McGraw-Hill Education. Kindle Edition.
Organochlorine insecticides (Chlorinated ethane derivatives)
DDT, methoxychlor
sodium channel activators
poorly absorbed through skin
acute oral tox -> tremors, convulsions, seizures, hyperactivity, hyper-susceptibility to stimuli; death due to respiratory failure
chronic tox -> hepatocellular hypertrophy, CYP induction, liver cancer (rat); stored in adipose tissue; endocrine active; possible association with testicular cancer
estrogenic effects
Pyrethroids
synthetic pyrethrins
very potent and not stable in environment
low mammalian tox
poisoning manifests as hypersensivity, tremor, seizures
activate voltage gated sodium channels (Types 1 and 2)
Type II pyrethroids also bind to and inhibit GABAa-gated chloride channels
do not require bioactivation
Carbamate Ester Insecticides
NAMES
aldicarb (Temik)
carbaryl (Sevin)