Renin/Angiotesnin system Flashcards Preview

Toxicology and Pharmacology > Renin/Angiotesnin system > Flashcards

Flashcards in Renin/Angiotesnin system Deck (40):
1

What works synergistically with the RAAS?

The SNS

(Increase SNS activity results in increased Renin release, also directly results in increased NaCl reuptake, vasocontriction)

2

What is the RAAS a critical part of?

The baroreflex system (long term control)

Thus controls blood pressure

3

How does RAAS control blood pressure?

Alters vascular tone (potent vasocontrictor)
Controls natriuresis (NaCL uptake)

4

RAAS activation does what to blood pressure?

Increases it

5

Where is renin released?

Renin is released from the juxtaglomerular cells.

6

What sort of enzyme is renin?

A proteolytic enzyme

7

What does Renin do?

Converts angiotensinogin into ANG1

8

What converts ANG1 into ANG2?

ACE

-Cleaves 2 AA

9

Where is ACE located?

Primarily in endothelial cells (mostly lungs)

10

What is the effect of ANG2?

Potent vasocontrictor at AT1 receptors

11

What causes renin release?

Increased Symp
Decreased NaCl past macula dense
Decrease af art bp (renal perfusion pressure)
Beta-agonists

12

What does ANG2 activation of AT1 result in?

(1) Vascular growth
- Hyperplasia
- Hypertrophy

(2) Vasocontriction
- Direct AT1
- Via increased NE release from SNS

(3) Salt Retention
- Aldosterone secretion when ANG 2 present
- Tubular Na reabsorption

13

What are agonists that cause smooth muscle contraction?

Hisamine
Angiotensin
NE

All increase Ca influx

14

What prevents smooth muscle contraction?

Ca channel blockers

15

What happens beyond ANG2?

ANG2 can be converted into ANG3 and ANG4

One AA cleaved in both cases

16

What is the function of ANG3?

Promotes aldosterone secretion

17

What is the function of ANG4?

Inhibition of clot clearance

18

How many AA is ANG1,2?

10AA
8AA

19

When is aldosterone released?

Hyperkalemia
ANG2 present

20

What is the action of aldosterone?

Bind to aldosterone receptor and causes increase apical NA channel expression and increased basolateral Na/K transporters

Increased K secretion

21

What are drug targets in the RAAS?

ACE inhibitors
ARB's (ang recep blockers) (antagonist)
Aldosterone antagonists
Ca channel blockers
Diuretics
Beta blockers

22

Whats an example of an ACE inhibitor?

Ciliazipril

23

How do ACE inhibitors work?

mimic section of ANG1 that binds to ACE, therefore binds in its place preventing ANG conversion

24

What is the dual effect of ACE inhibitors?

ACE has similar binding site to Kinase 2.
Kinase 2 is used to degrade bradykinin.

Thus ACE Inhibitors block kinase 2 action also and lead to increased bradykinin levels which has two main symptoms of:

1) Dry Cough
2) Angioedema

25

What is angioedema?

leakiness of blood vessels in vasodilation in lips, larynx, pharynx (occlude airways)

26

What is an example of an ARB?

Losartan

27

What sort of action does an ARBs have?

Competitive reversible antagonist at AT1

28

Which should be used ARB or ACE inhibitors?

ACE inhibitors are generally more effect.

A combination causes renal damage.

ARB used as substitute for ARB's

29

How would you block aldosterone action?

Aldosterone antagonists

30

Whats an example of an aldosterone antagonist?

Spirinolactone

31

What does spirinolactone do?

Prevents Na reabsorption caused by aldosterone

32

How do calcium channel blockers work?

Block channels preventing smooth muscle contraction therefore no change in vasomotor tone and no increase in blood pressure.

33

Whats an example of a Ca channel blocker?

Verapamil

34

What do diuretics do?

Oppose ANG2 effects

35

What is the function of a diuretic primarily/

increases na excretion

36

Whats an example of a diuretic?

Amilorides

Works by blocking Na channels, therefore no absorption of Na in the kidney

37

How do beta blockers work?

Competitive antagonists at b adrenergic receptors

primarily B1

38

What does B blocker use result in?

Decreased contractility
Decreased Renin secretion

39

Whats an example of a Beta blocker?

Metoprolol

40

What are three types or diuretics?

Amiloride - blocks Na channels (connecting duct)
Thiazides - Inhibits NaCl transporters
Loop Diuretics - 2ClNaK transporter inhibited