Endocrine Disruptors

Question 1

What are the non-classical endocrine glands, and what hormones do they release?

Answer 1

Brain - especially the hypothalamus

Kidney: renin, vit D, EPO

Heart: ANP and BNP

Liver: IGF-1

GI - small intestine, stomach: serotonin, ghrelin

Question 2

What is renin and where is it produced?

Answer 2

glycoprotein produced in the juxtaglomerular apparatus of afferent arterioles

Question 3

What does renin do?

Answer 3

regulator of arteriolar diameter

cleaves angiotensinogen to angiotensin I

Question 4

What does EPO do?

Answer 4

stimulates proerythroblasts and differentiation of RBCs (increases cell number)

Question 5

What is EPO regulated by?

Answer 5

anemia, thyroid hormone, hypoxia (high altitude), norepinephrine

androgens stimulate, estrogens inhibit

Question 6

What is a major side effect of raising hematocrit too quickly?

Answer 6

hypertension, which can lead to encephaly, seizures

Question 7

What are some other effects of doping?

Answer 7

red cell aplasia - likely due to the injections, and not EPO itself

transgenic overexpression of EPO: Mice had demyelinating neuropathy, muscle degeneration, degenerative liver/kidney disease, shorter life span. No cardiovascular issues.

Question 8

What are the effects of ANP and BNP?

Answer 8

decrease vascular smooth muscle tone

decrease peripheral vascular resistance

increase capillary permeability

Question 9

What is the definition of an endocrine disruptor?

Answer 9

chemicals that may interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife

Question 10

What are PCBs?

Answer 10

Polychlorinated biphenyl

Question 11

What do PCBs do?

Answer 11

compete with thyroid binding to its transport proteins in blood (TRR, TBG)

Question 12

What are the effects of PCB?

Answer 12

increased breakdown of TH with a compensatory increase in production by the thyroid gland

goiter, can cause cancer, suppress immune function, reduce sperm count, and result in neurological deficits

Question 13

What is Diethylstilbestrol (DES)?

Answer 13

non-steroidal synthetic estrogen used in cattle feed

given to women from 1940-1970 to reduce complications

used as a prostate cancer treatment

Question 14

What was the result of DES toxicity?

Answer 14

“DES daughters” = 40% increase in cervical/vaginal cancers

Question 15

What are some endocrine compounds found in water?

Answer 15

Pesticides (Atrazine)
Estrogens given to livestock
Industrial chemicals (bisphenol-A)

Question 16

are birth controls found in water?

Answer 16

Synthetic estrogen (EE2) is minimal or nonexistent in drinking water

Question 17

What is BPA used for?

Answer 17

food packaging, toys, lining of canned foods and beverages

Question 18

What are the physiological consequences of BPA?

Answer 18

estrogenic, obesogenic, neurological effects, antagonist for thyroid hormone receptor, reproductive and developmental effects (men and women), cardiovascular disease - evidence for arrhythmias and atherosclerosis

Question 19

What is an issue with BPA branding?

Answer 19

BPA substitutes – BPS and BPF

As of July 2015 there were 32 studies. Most found that they had similar endocrine actions as BPA

Recent study showed BPS is risk factor for developing T2DM.

Consumers can buy products that are labelled “BPA-free” and these products likely contain BPS or BPF.