HAHs Flashcards Preview

TOX 412 > HAHs > Flashcards

Flashcards in HAHs Deck (8)
Loading flashcards...
1
Q

what usually dictates the toxicity of HAHs?

A

the more chlorinated the HAH, more persistence and toxic the molecule

2
Q

what is the most toxic HAH?

A

2,3,7,8-tetrachlorodibenzene-para-dioxin (2,3,7,8-TCDD or TCDD)

3
Q

half life of HAHs?

A

7-10 years

4
Q

what is the prototypes of HAHs?

A

TCDD

5
Q

what are the biological effects of HAHs?

A
  1. wasting syndrome (anorexia)
  2. thymic atrophy
  3. chloracne
  4. hepatotoxicity
  5. IMMUNE SUPPRESSION
  6. REPRO TOX
  7. TERATOGENICITY
  8. CARCINOGENICITY (non-genotoxic)
  9. endocrine disruption
  10. enzyme induction
6
Q

mech of tox of dioxins

A
  • receptor specific to TCDD found in cytosol of hepatocytes;–known as aryl hydrocarbon receptor; orphan receptor; TCDD diffuses through cell into cytosol–binds to AhR–>dimerizes IN NUCLEUS and binds to DNA–transcribes CYP1a1, CYP1a2,nqo!,ALDh3a1, ugt1a6, and Gsta1 gene–make good biomarkers of AhR agonist exposure in wildlife
  • also uncouples CYP–?produces ROS
7
Q

sources of PAHs

A

combustion of organic material– industrial (smelting);
domestic (municipal incinerators)
motor vehicle exhaust
forst fires–big contributor
tobacco
bbqs
major source in NA–burning wood in fireplaces

8
Q

biochemical effects of HAHs?

A

modulate hormones, receptors, growth factors, and receptors; enzyme induction