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Flashcards in Cardio 3 Deck (34):
1

What does white adipose tissue secrete and what does this signal by?

Leptin - ObR receptor via POMC

2

What pathway does leptin activate?

JAK-STAT

3

What does JAK-STAT lead to?

Cell growth and proliferation

4

What does MAPK lead to?

Cell growth and differentiation

5

What does PI3K lead to?

Growth, proliferation and differentiation

6

What happens when megalin binds to leptin?

Signalling cascade

7

What is the main perpetrator for increased BP associated with obesity?

Leptin

8

What happens to leptin levels when on high fat diet?

Increase

9

What does abnormal leptin signalling cause?

Obesity

10

What happens if you change the leptin pathway?

No obesity associated hypertension

11

What happens if the leptin concentration is restored?

Heart rate and hypertension increased

12

What does leptin target in the brain?

DMH to regulate BP

13

What happens if you turn off leptin signalling via leptin receptor?

Prevent increased BP

14

Is leptin present in the urine in obesity?

No - kidneys able to process leptin

15

What does leptin do to the glomerulus?

Alters it - increases TGF-B1 - increases collagen and fibrosis

16

What happens when proximal tubule cells are exposed to more leptin?

More phosphorylated and active proteins - megalin signals by mTORC2 instead of JAK-STAT

17

What proteins does the glomerulus filter?

Proteins less than 70kda - including albumin

18

What % of albumin is filtered and reabsorbed?

0.06-3%, 96%

19

What is the function of podocytes?

Allow selective passage of contents into the filtrate

20

What is megalin?

Scavenger receptor in proximal tubule that binds to ligands

21

What is the function of megalin?

Bring ligands into cell for degradation or transcytosis

22

What does the amount of megalin determine?

The quantity of proteins that will be degraded

23

What does meaglin do when cleaved by peptide transferases?

Acts as a signal transducer - regulates gene transcription

24

What does AMPK do?

Regulates cell energy homeostasis

25

What activates AMPK?

Leptin and adiponectin

26

What does obesity do to AMPK?

Blocks it - increases inflammation

27

What does activation of AMPK in type 2 diabetes prevent?

Renal hypertophy

28

What does AMPK inhibition decrease?

TGF-B1 secretion

29

What is AMPK the driver for, and what is this initiated by?

Fibrotic change - leptin binding to megalin

30

Where is leptin secreted from and what is the normal plasma level?

Secreted from placenta, GIT, mammary epithelium
Normal concentration is 59.5ng/mL

31

What is the direct action of leptin and why?

Increase BP - activation of nerves that supply CV system

32

What does leptin up regulate in the proximal tubule cells?

ERK 1/2, AMPK, mTOR

33

What % of Australians are obese?

63%

34

How does leptin reduce metabolic activity?

mTOR