Endocrine Toxicology

Question 1

What is an EDC?

Answer 1

Endocrine Disruptor

Question 2

What is the DOHaD?

Answer 2

Developmental Origins of Health and Disease
Based on evidence that the roots of many disease and dysfunctions occur very early in life, especially in the embryo, fetus, infant, and child

Question 3

What human system is particularly sensitive to EDC exposures?

Answer 3

Nervous system

Question 4

When are early exposures to EDCs manifested in life?

Answer 4

Any time

Question 5

Can endocrine disruptors canse remethylation of primordial germ cell DNA?

Answer 5

Yes

Question 6

What are the three targets of Testosterone?

Answer 6

Muscle (inc in strength/volume)
Liver (synthesis of serum proteins)
Brain (libido, aggression)

Question 7

What are the potential sites for endocrine disruption?

Answer 7

Brian (releasing factors)
Pituirary (LH/FSH/GH)
Gonad (estrogens/androgens)
Liver (enzymes)
Blood (binding proteins)

Question 8

What are three EDCs in wildlife?

Answer 8

Eggshell thinning in raptors - DDT
Beak, skeletal, reproductive abnormalities from PCOBs
Intersex fish below sewage plants

Question 9

Describe the Hypothalamic-pituitary-end organ axis for the thyroid

Answer 9

Hypo: TRH
Pit: TSH
Thy: T3/T4

Question 10

Exposure to xenobiotics can lead to _____ which causes _____

Answer 10

Liver microsomal induction

Thyroid follicular cell hyperplasia/neoplasia

Question 11

Between Hypertrophy and hyperplasia, which leads to carcinoma?

Answer 11

Hyperplasia

Question 12

What is the effect of Bisphenol A (BPA)?

Answer 12

Abnormal chromosome numbers/aneuploidy

Question 13

Phat are pthalates? Name one

Answer 13

Plasticizers

DEHP

Question 14

What is the mechanism of toxicity for DEHP?

Answer 14

Testicular dysgenesis syndrome in males
Acts directly on Leydig cells
Decreses enzyme synthesis/gene expression (Leydig cells)
Decreases Cyclin D in sertoli cells

Causes Hypospadias, Cryptorchidism, multinucleated gonocytes

Question 15

Why are BPS and BPF termed “regrettable replacements”?

Answer 15

“Based on the current literature, BPS and BPF are as hormonally active as BPA, and have endocrine disrupting effects”

Question 16

What does the CIHR team grand do?

Answer 16

Design and testing of Green Plasticisers: Replacements for pthalates

Question 17

How do you test plasticizer qualities?

Answer 17

Have to be as good as current plasticizers (benchmark = DEHP)

• Glass transition temperature
• Tensile strength
• % elongation

Question 18

Did exposure to BDB or DOS produce multinucleated gonocytes at PND3?

Answer 18

No

Question 19

Name 4 types of ECDs

Answer 19

BPA
Pthalates
Brominated Flame Retardants
Perfluorans