Xenoestrogens and Endocrine Disruption

Question 1

Endocrine disrupter is a foreign

Answer 1

substance or mixture that alters the functioning of the endocrine system and consequently causes adverse health effects on an intact organism and/or its progeny

Question 2

endocrine disruptors include a wide variety of chemical classes including

Answer 2

pharmaceutical agents, pesticides, plastics, pollutants

Question 3

endocrine disruptors can act through 4 different ways:

Answer 3

• nuclear hormone receptors
• nonsteroid receptors
• transcriptional co-activator
• enzymatic pathways involved in steroid biosynthesis or metabolism

Question 4

Obesogens

Answer 4

EDs that promote weight gain

Question 5

Obesogens can promote weight gain directly by acting on

Answer 5

fat cells to increase their number of storage of fat

Question 6

Obesogens can promote weight gain indirectly by acting on

Answer 6

mechanisms for satiety and appetite or by altering the basal metabolic rate of storage of calories

Question 7

xenoestrogen

Answer 7

type of xenogene that imitates estrogen

Question 8

orphan receptor

Answer 8

a receptor that has no known ligand

Question 9

endocrine system

Answer 9

collection of glands that secretes hormones directly into the circulatory system and are carried toward distant target organs - moves SLOWLY

Question 10

BPA is the most

Answer 10

prominent ED known

Question 11

does BPA have strong or weak activity?

Answer 11

weak

Question 12

does BPA have agonist or antagonist effects?

Answer 12

both! so it’s unpredictable

Question 13

response from BPA depends on 3 things

Answer 13

1. level
2. expression of receptors
3. availability of co-factors

Question 14

Window’s of susceptibility - the timing of the exposure is

Answer 14

critical component of BPA toxicity

Question 15

what are the most vulnerable timing periods

Answer 15

prenatal and neonatal

Question 16

how does BPA effect epigenetics?

Answer 16

it induces hypomethylation on CpG islands in the gene regulator regions of several genes in agouti mice

but it also can hypermetylate

Question 17

what is the most potent AhR agonist?

Answer 17

TCDD

Question 18

The low dose hypothesis says that EDs can have effects at low doses that are not

Answer 18

predicted by effects at higher doses

-they have different effects at lower doses and these cannot be predicted by the effects at higher doses

Question 19

what did the EPA say about the low dose hypothesis?

Answer 19

that there is not enough evidence to prove it