1_IntroToEndocrinology

Question 1

How is NE synthesized

Answer 1

from Tyrosine

Question 2

How is epinephrine synthesized?

Answer 2

Norepi + SAM via phenylethanolamine-N-methyltransferase

Question 3

Which catecholamine is primarily a neurotransmitter?

Answer 3

NE

Question 4

Describe the action of an autocrine factor?

Answer 4

acts on the same cell type nearby

Question 5

Describe the action of a paracrine factor.

Answer 5

acts on many nearby cell types

Question 6

Describe the action of an intracrine factor.

Answer 6

acts inside the same cell, but also in a minor fashion through paracrine or endocrine mechanisms. Linked to nuclear receptors.

Question 7

what molecules act as intracrine factors?

Answer 7

intermediate metabolites, FFAs, oxysterols, retinoids, phospholipids

Question 8

what is the structure of arachidonic acid?

Answer 8

20:4 (delta)5,8,11,14

Question 9

what is the structure of linoleic acid?

Answer 9

18:2 (delta)9,12

Question 10

describe the pharmacokinetics of eicosanoids.

Answer 10

short half-life; metabolized in lung and surrounding tissues

Question 11

What molecules fall in the eicosanoid category?

Answer 11

PGE2, TX, PGI2, leukotrienes, lipoxins, PGE1

Question 12

What is the major function of the eicosanoids?

Answer 12

local regulation of blood flow

Question 13

How are cytokines classified?

Answer 13

by structure and by function

Question 14

What is the function of the type 1 cytokines?

Answer 14

innate immune response

Question 15

What is the function of the type 2 cytokines?

Answer 15

acquired immune response

Question 16

What are the 4 structural classes of cytokines?

Answer 16

1) 4 alpha-helix bundle: IL2, IL10, interferon; 2) IL-1, 3) IL-17; 4) chemokines (NCP-1)

Question 17

What are cytokines?

Answer 17

soluble peptides/glycoproteins secreted to act distally

Question 18

What factors are secreted in an autocrine or paracrine fashion?

Answer 18

eicosanoids, cytokines, adipokines

Question 19

What are the functions of miRNA?

Answer 19

mRNA target cleavage; translational repression; mRNA deadenylation

Question 20

How are miRNAs released into the blood?

Answer 20

protein complexes; apoptotic bodies; exosomes

Question 21

What are the types of hormones?

Answer 21

1) intracrine; 2) autocrine/paracrine, 3) endocrine; 4) neuroendocrine; 5) miRNA

Question 22

How are hormone concentrations regulated?

Answer 22

1) secretion; 2) transport; 3) clearance

Question 23

Describe the relative half-lives of peptides, catecholamines, and steroids.

Answer 23

catecholamines = seconds; peptides = minutes-days; steroids = hours

Question 24

How are hormones cleared?

Answer 24

binding, catabolism, excretion

Question 25

What is a diurnal rhythm?

Answer 25

daily

Question 26

what is an infradian rhythm?

Answer 26

longer & more varied than diurnal

Question 27

What hormones function on diurnal rhythms?

Answer 27

cortisol, androstenedione, DHEA; all are higher in the morning

Question 28

What processes function on infradian rhythms?

Answer 28

menstruation, breeding, seasonal rhythms

Question 29

How can hormone catabolism be prevented?

Answer 29

point mutations

Question 30

What are examples of adipokines?

Answer 30

leptin, adiponectin, TNF-alpha, PAI-1, RBP-4

Question 31

What are the functions of adipokines?

Answer 31

appetite control and inflammation

Question 32

What did Arnold Berthold do?

Answer 32

"ablation and replacement" of roosters testes to evaluate sex behavior

Question 33

What is the function of a signal sequence, and on which type of molecule is it located?

Answer 33

the first AA sequence which allows pre-prohormoneof a peptide hormone entry into rough ER during translation

Question 34

How are peptide hormones generally secreted?

Answer 34

as the prohormone

Question 35

What are the classes of hormones?

Answer 35

protein/peptide, steroid, tyrosine derivatives

Question 36

What is the precurose for steroid hormones?

Answer 36

cholesterol

Question 37

What is the rate-limiting step in steroid synthesis?

Answer 37

cholesterol via CYP450scc to pregnenolone

Question 38

What is T4?

Answer 38

thyroxine

Question 39

What is T3?

Answer 39

3,5,3'-triiodothyronine

Question 40

What are the precursors for eicosanoids?

Answer 40

arachidonic & linoleic acids

Question 41

Describe the relative storage characteristics between the 3 classes of hormones?

Answer 41

peptides (most) >> catecholamines >> steroids

Question 42

Which classes of hormones are bound in the plasma?

Answer 42

steroids (90%) and the peptides CRH & GH

Question 43

Which classes of hormones are free in the plasma?

Answer 43

peptides and catecholamines

Question 44

On what order of concentration are the hormones in the plasma?

Answer 44

ng/mL or pg/mL