4_1Adipose

Question 1

What are the functions of adipose?

Answer 1

1) insulation and organ protection; 2) drug metabolism; 3) energy storage/expenditure; 4) endocrine

Question 2

What are the endocrine functions of adipose?

Answer 2

1) regulation of body weight; 2) insulin sensitivity; 3) inflammation

Question 3

From what does adipose protect organs?

Answer 3

protects from intertial injury and excessive movement

Question 4

Where is brown fat stored?

Answer 4

1) supraclavicular; 2) subscapular

Question 5

What are the types of adipose?

Answer 5

WAT (SQ and Visceral) and BAT

Question 6

How does adipose tissue vary?

Answer 6

by type and location

Question 7

Describe the cellularity of VAT

Answer 7

mostly unilocular

Question 8

Describe the cellularity of BAT

Answer 8

multilocular and uniform

Question 9

Describe the cellularity of SAT.

Answer 9

unilocular with some multilocular (more heterogeneous than VAT)

Question 10

What are pericytes?

Answer 10

adipocyte stem cells

Question 11

Where are pericytes located?

Answer 11

lining of vasculature with mature adipocytes

Question 12

What is the function of WAT?

Answer 12

storage and endocrine

Question 13

What is the function of BAT?

Answer 13

non-shivering thermogenesis

Question 14

What was dinitrophenolamine (DNP)?

Answer 14

a former drug that induced beiging by uncoupline the H+ gradient; no longer on market due to abuse and OD

Question 15

Which adipocytes are associated with the healthy pear-shape?

Answer 15

SAT

Question 16

Which adipocytes are associated with the unhealthy apple shape?

Answer 16

VAT

Question 17

What are the 2 types of WAT?

Answer 17

SAT and VAT

Question 18

What type of fat is associated with inflammation and metabolic disease?

Answer 18

VAT!

Question 19

How do adipocytes vary?

Answer 19

cellularity and function

Question 20

Describe the presence of BAT throughout life.

Answer 20

abundant in newborns and declines with age; induced by constant cold

Question 21

What are beige adipocytes?

Answer 21

an intermediate phenotype that is susceptible to environmental and pharmacologial induction

Question 22

What is the function of uncoupling proteins (UCPs)?

Answer 22

uncouple the ATP/H+ gradient to allow H+ travel from intermembrane space to matrix

Question 23

What proteins are upregulated in beige adipocytes?

Answer 23

UCP1 (also UCP-2 and -3)

Question 24

What cells do Myf5+ cells differentiate to?

Answer 24

white or beige adipocytes

Question 25

What cells do Myf5- cell differentiate to?

Answer 25

brown adipocytes

Question 26

What is transdifferentiation?

Answer 26

the induction of white fat to beige fat

Question 27

What substances induce transdifferentiation in animal models?

Answer 27

norepi and beta-3 agonists

Question 28

What is the precursor to Myf5+/- cells?

Answer 28

mesenchymal cell

Question 29

What is DGAT?

Answer 29

diacylglycerol transferase

Question 30

What is ATGL?

Answer 30

adipocyte TG lipase

Question 31

What are the pathways for TG synthesis in adipose?

Answer 31

1) from FFAs (major); 2) de novo from glucose (minor)

Question 32

How is TG synthesis stimulated in adipose?

Answer 32

insulin

Question 33

What reaction is catalyzed by ATGL?

Answer 33

TG -- DAG

Question 34

What reaction is catalyzed by HSL?

Answer 34

DAG -- MAG -- FA + glycerol

Question 35

What is the function of perilipin?

Answer 35

when de-phosphorylated, it prevents lipase access to TGs

Question 36

What substances stimulate the phosphorylation of perilipin?

Answer 36

catecholamines

Question 37

What is the function of catecholamines in adipose?

Answer 37

phosphorylation of perilipin and HSL

Question 38

Which form of HSL is active?

Answer 38

phosphorylated

Question 39

What form of perilipin allows ATGL access to TGs?

Answer 39

phosphorylated

Question 40

How do catecholamines initiate signal transduction?

Answer 40

bind to G-alpha-S to initate the cAMP/PKA pathway

Question 41

What is the primary function of leptin?

Answer 41

long-term regulation of body weight to limit weight gain/loss during positive/negative energy balances

Question 42

What are the effects of leptin?

Answer 42

increased energy expenditure: 1) decreased SNS activity; 2) decreased TSH; 3) decreased GnRH; 4) increased glucocorticoids;;; decreased food intake

Question 43

When is leptin released?

Answer 43

more released during positive energy balance

Question 44

How do leptin levels vary?

Answer 44

levels of synthesis and secretion correlate with changes in adipose mass (no oscillation between meals)

Question 45

How is adipose defended (with regard to liposuction report)?

Answer 45

removal of SQ fat yields decreased leptin. Decreased leptin decreases energy expenditure. Fat returns as VAT

Question 46

Why do most fatty acids leave the adipose for beta-oxidation?

Answer 46

adipose lacks lots of mitochondria

Question 47

What is the de novo pathway for TG synthesis?

Answer 47

glucose yields G3P and pyruvate. Pyruvate converted to acetyl-CoA and to fatty acids. Fatty acids are activated and esterified via DGAT to G3P

Question 48

What are the anabolic fates of DAG?

Answer 48

1) TG, 2) phospholipid synthesis