Lecture 11

Question 1

What are the non-classical endocrine glands?

Answer 1

Brain-especially hypothalamus
Kidney- renin, vitamin D, erythropoietin
Heart-ANP, BNP
Liver-IGF-I
GI-small intestine, stomach (serotonin, ghrelin)

Question 2

Where is renin produced and what does it do?

Answer 2

glycoprotein produced in the juxtaglomerular cells of afferent arterioles

• important regulator of arteriolar diameter
• cleaves angiotensinogen to angiotensin 1 (precursor for angiotensin 2)

Question 3

What does EPO do?

Answer 3

24 kDa protein made in the kidney; tyrosine-linked kinase receptor
-stimulates proerythroblasts and differentiation of RBCs (increases cell number)

Question 4

What is EPO regulated by?

Answer 4

anemia
thyroid hormone 
hypoxia
norepinephrine
androgens stimulate, estrogens inhibit

Question 5

WHy is doping with EPO bad?

Answer 5

raising hematocrit too quickly=hypertension
-severe hypertension–> encephaly and seizure

Pure red cell aplasia-but now thought to be bud to injection prep not EPO

Question 6

The heart makes ANP and BNP, what do they do?

Answer 6

released in response to high blood volume

1) decrease vascular smooth muscle tone
2) decrease peripheral resistance
3) increase capillary permeability
4) generates a significant increase in hematocrit!!!

ANP-atrial myocytes-respond to blood volume
BNP-Ventricular myocytes-respond to stretch

• both trigger through NPR receptor
• decrease in renin and ADH

Question 7

Is ANP or BNP used as a diagnostic tool? Why?

Answer 7

BNP-longer half life
-normal levels can rule out congestive heart failure
higher levels with heart and renal failure
-lower levels with obesity, increase with age, higher levels in women

Question 8

PCBs are environmental endocrine disruptors what do they do?

Answer 8

compete with thyroid hormone binding to transport protein in the blood
Result:
-increased breakdown of thyroid hormone
-compensatory excessive production by thyroid gland
-goiter (enlarged thyroid gland)
-also causes cancer, immune function suppression (atrophied thymus), reduced sperm count, neurological defects.

Question 9

DES is an environmental endocrine disruptor what is it?

Answer 9

non-steroidal synthetic estrogen
DES daughters=40% increase in cervical/vaginal cancers
-also used to treat prostate cancer and livestock

Question 10

Is there birth control in water? What other estrogenic compounds are in the water?

Answer 10

-synthetic estrogen EE2 is minimal or nonexistent in drinking water

Other estrogenic compounds:

1. pesticides (atrazine)
2. estrogen given to livestock
3. industrial chemicals (bisphenol-A)