Endocrine IX: Endocrine Disruptors

Question 1

What is the function of EPO produced by the kidney?

Answer 1

It stimulates proerythroblasts and differentiation of RBCs (increases cell #)

Question 2

What is “doping”?

Answer 2

increasing the # of RBCs by taking erythropoietin, which promotes RBC production

Question 3

Is ANP or BNP (or both) a useful diagnostic tool?

Answer 3

BNP because it has a longer half-life than ANP. Normal levels of BNP can rule out CHF. Higher levels are associated with heart and renal failure, and lower levels are associated with obesity.

Question 4

What is the main effect of ANP and BNP?

Answer 4

excretion of Na+ (natriuresis)

Question 5

How do ANP and BNP affect blood vessel function?

Answer 5

-decr. vascular sm. muscle tone
-decr. peripheral vascular resis.
-incr. capillary perm.
(the above factors plus decreased water reabsorption generate a significant increase in hematocrit)

Question 6

What is the most well-studied environmental contaminant?

Answer 6

PCBs (polychlorinated biphenyls)

Question 7

What do PCBs interfere with physiologically?

Answer 7

They compete with thyroid hormone binding to its transport protein in the blood (TTR, TBG), causing increased breakdown of thyroid hormone and compensatory excessive production by the thyroid gland, leading to goiter. They also cause cancer, suppress immune function, reduce sperm count, and result in certain neurological deficits.

Question 8

What are the 3 major regulators of blood pressure?

Answer 8

• AVP
• Aldosterone
• ANP/BNP

Question 9

What is diethylstilbestrol (DES)?

Answer 9

a non-steroidal synthetic androgen used in cattle feed and formerly given to pregnant women to reduce complications; daughters born to women who were given DES known to have 40% increase in cervical and vaginal cancers

Question 10

Is synthetic estrogen (EE2) present in the water?

Answer 10

No, it is minimal or nonexistent. However, there ARE other estrogenic compounds in the water, including pesticides (atrazine), estrogens given to livestock, and industrial chemicals (BPA).

Question 11

There is more ____ produced annually than any other chemical. Everyone is exposed to it all the time (93% of Americans have detectable amounts in urine).

Answer 11

BPA

Question 12

Is there a federal ban on BPA?

Answer 12

No, but public pressure pushed manufacturers to stop using BPA and market items as BPA-free.

Question 13

What are some of the physiological consequences of BPA exposure?

Answer 13

• estrogenic
• obesogenic and diabetogenic
• neurological effects
• antagonist for thyroid hormone
• reproductive and developmental effects
• CVD (arrhythmias and atheroscelorsis)

Question 14

What are the BPA substitutes? Are they safe?

Answer 14

BPS and BPF; not much is known about them, so they may be even worse than BPA; recent study showed that BPS is a risk factor for developing T2DM

Question 15

What is a major side effect of doping?

Answer 15

increasing hematocrit too quickly can cause HTN, and severe HTN can lead to encephalopathy and seizures

Question 16

Androgens ______ and estrogens _______ erythropoietin.

Answer 16

stimulate; inhibit

Question 17

Which bond does renin split?

Answer 17

Leu-Val bond in angiotensinogen

Question 18

What are the non-classical endocrine organs?

Answer 18

kidney, heart, liver, small intestine, stomach

Question 19

What is a non-classical endocrine organ?

Answer 19

organs that contain specialized cells within them that make hormones (vs. classical endocrine gland, which is entirely dedicated to endocrine function)