Week 3 Adipose Tissue Dysfunction

Question 1

how does adipose tissue appear under a microscope?

Answer 1

thin walled empty vacuole with nucleus pushed to periphery of cell (appear empty becuase stain is hydrophobic and dissolved the fat)

Question 2

what is brown fat?

Answer 2

fat that is important in heat production thermogenesis

Question 3

where/in who do we see brown fat?

Answer 3

newborns have quite a bit of brown fat, amount decreases with age and remains only around kidney, large vessels, neck and back at older age

Question 4

how does brown adipose tissue appear under a micrsocope?

Answer 4

smaller, more numerous fat vacuoles within each adipocyte (than white adipose tissue)

Question 5

describe the vascularity and innervation of brown adipose tissue?

Answer 5

highly vascular and innervated

Question 6

what is metabolic syndrome?

Answer 6

A cluster of conditions (high BP, high cholesterol, hyperglycemia, high visceral fat) that occur together, increasing your risk of heart disease, diabetes, and stroke

Question 7

what is visceral obesity?

Answer 7

fat surrounding organs

Question 8

what does adpiose tissue consist of?

Answer 8

macrophages, adipocytes, fibroblasts, pre-adipocytes

Question 9

what is role of fibroblasts?

Answer 9

make ECM and collagen

Question 10

what is role of pre-adipocytes?

Answer 10

stemm cell-like that generate new adipose cells

Question 11

what is role of macrophages?

Answer 11

seen mostly in visceral adipose, recruited to adipocytes as they grow larger, increase inflammation and decrease adiponectin

Question 12

what is the role of white adipose tissue?3

Answer 12

insulate body, store and release FFAs, protect organs

Question 13

what is role of lipoproteins such as chylomicrons?

Answer 13

transport triglycerides from intestines to adipose tissue

Question 14

what is role of lipoprotein lipase?

Answer 14

separates TGs from lipoproteins so they can be stored in adipocytes

Question 15

what is role of hormone sensitive lipase?

Answer 15

liberates FFAs from adipocytes to increase FFAs in bloods

Question 16

what effect does insulin have on LPL and HSL

Answer 16

promotes LPL and inhibits HSL (promotes TG sotrage)

Question 17

why do individuals with type II diabetes get fatter?

Answer 17

increased insulin levels increases the amount of TG stored in adipocytes (LPL increases and HSL decreases)

Question 18

what are adipokines?

Answer 18

the endocrine hormones of adipocytes

Question 19

in general, as adipose volume increases, what occurs to adipokine levels?

Answer 19

increase as well (except for adiponectin!)

Question 20

Leptin: main site of production, role 2, stimulated by

Answer 20

mainly produced in SubQ adipocytes, increases lipid oxidation in liver and lipolysis in muscle and adipose tissue (fat burner)
stim by FFAs and insulin

Question 21

Adiponectin: role 3

Answer 21

anti-atherosclerotic, enhances insulin sensitivity, increases glucose uptake

Question 22

when is adiponectin synthesis/activity reduced?3

Answer 22

obesity, insulin resistance, metabolic syndrome

Question 23

what is the role of IL-6? where is it produced

Answer 23

recruits macrophages to adipose tissue, visceral adipocytes

Question 24

which hormones are primarily produced in visceral adipose 2

Answer 24

angiotensinogen, IL-6

Question 25

where is leptin primarily produced

Answer 25

SubQ adipose

Question 26

are macrophages more prevelant in visceral or SubQ adipose?

Answer 26

visceral

Question 27

what is the signaling between adipocytes and macrophages

Answer 27

large adipocytes release FFAs–>macrophages releases TNF-alpha–>adipocytes induce lipolysis and express IL-6–>more macrophages are recruited–>inflamation seen in obesity occurs (adipose tissue dysfunction)

Question 28

obesity is associated with what form of inflammation? attributed to?

Answer 28

a chronic low grade inflammatory state. attributed to increased macrophages

Question 29

what is meant by adipose tissue dysfunciton?

Answer 29

this denotes a state of hypersecretion of pro-atherogenic, pro-inflammatory, and pro-diabetic adipocytokines

Question 30

who has more macrophages in their adipose tissue skinny or fat people?

Answer 30

fat

Question 31

macrophage number in adipose tissue correlates with…

Answer 31

insulin resistance

Question 32

how does insulin resistance occur in obese people?

Answer 32

the viscous cycle of inflamation and hyper-secretion seen in adipose of fat people releases FFAs. chronically high levels of FFA inhibits insulin signaling TNF-alpha also confers insulin resistance

Question 33

how does adiponectin increase insulin sensitivity?

Answer 33

trigger break down (oxidation) of FFAs in liver, inhibits glucose production

Question 34

what causes type II diabets (2)?

Answer 34

insulin resistance and a decreased insulin secretoty fxn of pancreatic beta-cells

Question 35

why is there increased insulin in fat people?

Answer 35

more insulin is made due to hyper-nutrition and insulin resistance…if this compensatory mechanism is exceeded type II diabetes occurs

Question 36

low adiponectin, and high IL-6, TNF-a, and leptin are associated with an increased risk of…

Answer 36

type II diabetes

Question 37

increased angioteninogen leads to what in obese people? (produced by dysfunctional adipocytes)

Answer 37

high blood pressure

Question 38

what is one explanation for the atherosclerosis seen in obese people?

Answer 38

a decrease in adiponectin

Question 39

low levels of which hormone is an independent predictor of future vascular disease?

Answer 39

adiponectin

Question 40

which hormone is a good measure of adipocyte dysfunction? why

Answer 40

adiponectin because it is only produced by adipocytes

Question 41

define independent risk factor

Answer 41

something is a significant contributor to a disease state

Question 42

what are the benefits of exercise in obese people?

Answer 42

reduce adipocyte size and modify adipocyte dysfunciton (decrease IL-6, TNF-alpha, leptin and increase adiponectin levles)