Lecture 39-41 Flashcards
What are pre-embryonic conceptuses usually resistance to?
Teratogens
What are the odds of birthing a completely normal healthy ifant?
Less than half
When is the spontaneous abotion most likely to occur?
Weeks 1 and 2
What is an EDC?
Endocrine disruption chemicals?
What are the functions of EDCs?
- Mimic endogenous hormones
- Block endogenous hormones
What EDCs mimic?
- Estrogenic chemicals (DES)
- Androgenic chemicals (Trenbolone)
What EDCs block?
Anti androgenic chemicals (Metabolites of DDT and vinclozlin)
Does a hormonal mimic trigger a hormonal response?
Yes, which can be hindering to the organism
What kind of hormonal block doesn’t bind to the binding site directly?
Steric Hindrance
What are the four levels that xenobiotics disrupt endocrine homeostasis at?
- Hormone synthesis (steroidogenesis) via enzymes
- Transport (prohibits binding to SHBG) by keeping endocrine hormones in local circulation and contributing to bioaccumulation
- Activation/Metabolism (Aromatase use/metabolic in activation/5A-reductase) via activation at target tissues and inactivation/degradation
- Receptor Binding (androgen receptor and oestrogen receptor) via internalization
What xenobiotic often affects steroidogenesis?
Phthalates (decreased 3B-HSD)
What xenobiotics often affects the use of aromatase to convert T to Oestradiol?
- Increased atrazine
- Decreased Tributyl Tin
What xenobiotic often affects the binding to SHBG?
Pesticides
What xenobiotics often affects metabolic inactivation/sulphation?
Sulphotransferases (PAHs and PCBs)
What xenobiotic often affects the use of 5a reductase?
Finasteride (proscar/propecia)
What xenobiotic often affects binding to androgen receptors?
p,p’-DDE
What xenobiotic often affects binding to oestrogen receptors?
o,p’-DDE
What the four main categories of EDCs?
- Androgenic
- Anti-androgenic
- Estrogenic
- Anti-estrogenic
What are examples of pharmaceutical androgenic EDCs?
Androgen Receptor Agonists (Trenbolone, Trenbolone acetate)
What are examples of pharmaceutical anti-androgenic EDCs?
- Androgen synthesis inhibitors (Ketoconazole)
- Androgen receptor antagonists (flutamide)
- 5a-reductase inhibitors (finasteride (Proscar, Propecia))
What are examples of environmental anti-androgenic EDCS?
- Androgen receptor antagonists (p,p’-DDT and its metabolites, vinclozolin and its metabolites)
- Androgen synthesis inhibitors (Phthalate esters)
What are examples of pharmaceutical estrogenic EDCs?
Estrogen receptor agonists (ethinyl estradiol, eiethylstilbestrol)
What are examples of environmental estrogenic EDCs?
- Estrogen receptor agonists (o,p’-DDT and its metabolites, Bisphenol A)
- Aromatase stimulant (Atrazine)
What are examples of pharmaceutical anti-estrogenic EDCs?
Aromatase inhibitors (Letrozole (Femara))