toxins

toxicants?

chemical or physical agents that produce adverse side effects on biological organisms

toxins

proteins produced by living organisms

poisons

toxicants that in small amounts cause death or illness

factors of toxicity

1. duration of exposure

2. route of exposure

3. dose

4. physiochemical properties

types of toxicants

1. metals

2. aggricultural chemicals: herb>pest>fungi> algae

3. food additives

4. solvents

5. therapeutic drugs

6. abused drugs

belladona/deadly night shade (treatment and symptoms

tropane alkaloids that block mAch receptors leading to suppressed PSNS and excess SNS

• treated using cholinesterase inhibitors

1. tachycardia

2. dilated pupils and blurry vision

3. decreased GI mobility and urinary hesitancy

4. decreased saliva

5. hallucinations and loss of balance

ex of tropane alkaloid

belladona

amanita muscarina

contains muscarine which activates PSNS and muscimol which is a GABA-a agonist that crossed the BBB

treated using mAch antagonist → atropine

1. abdominal cramping and pain

2. miosis

3. increased secretions

4. breathing difficulties

foxglove

contain digoxin a cardiac glycoside

treated using charcoal, fluid replacement and K+ rich food

fugue

tetradotoxin: blocks voltage gated calcium channels

tetradotoxin

fugue, blocks voltage gated Na+ channels

paralytic shellfish poisoning

consumption of seafood after a red algae bloom

contains saxitoxin→ blocks voltage gated Na+ channels s

sarin gas

irreversible AchE inhibitor

aminoglycosides

ototoxic

tetracycline

bone and teeth accumulation

paracetamol

liver dmg

methanol

eye damage

gentamycin

kidney damage

chloramphenicol in newborns

1. underdevelopped conjugation enzymes → impaired glucoronidation

2. increased plasma [chloramphenicol] causes gray syndrome

testing drug toxicity

1. LD50 → uses animal model

2. draize test → apply drug to eye

3. ames test → mutant bacteria with inability to synthesize histidine has drug added → if drug is a mutagen bacteria will be able to synthesize histidine

4. yellow card reporting scheme