Renin/Angiotesnin system Flashcards Preview

Toxicology and Pharmacology > Renin/Angiotesnin system > Flashcards

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

What works synergistically with the RAAS?

A

The SNS

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

2
Q

What is the RAAS a critical part of?

A

The baroreflex system (long term control)

Thus controls blood pressure

3
Q

How does RAAS control blood pressure?

A
Alters vascular tone (potent vasocontrictor)
Controls natriuresis (NaCL uptake)
4
Q

RAAS activation does what to blood pressure?

A

Increases it

5
Q

Where is renin released?

A

Renin is released from the juxtaglomerular cells.

6
Q

What sort of enzyme is renin?

A

A proteolytic enzyme

7
Q

What does Renin do?

A

Converts angiotensinogin into ANG1

8
Q

What converts ANG1 into ANG2?

A

ACE

-Cleaves 2 AA

9
Q

Where is ACE located?

A

Primarily in endothelial cells (mostly lungs)

10
Q

What is the effect of ANG2?

A

Potent vasocontrictor at AT1 receptors

11
Q

What causes renin release?

A

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

12
Q

What does ANG2 activation of AT1 result in?

A

(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
Q

What are agonists that cause smooth muscle contraction?

A

Hisamine
Angiotensin
NE

All increase Ca influx

14
Q

What prevents smooth muscle contraction?

A

Ca channel blockers

15
Q

What happens beyond ANG2?

A

ANG2 can be converted into ANG3 and ANG4

One AA cleaved in both cases

16
Q

What is the function of ANG3?

A

Promotes aldosterone secretion

17
Q

What is the function of ANG4?

A

Inhibition of clot clearance

18
Q

How many AA is ANG1,2?

A

10AA

8AA

19
Q

When is aldosterone released?

A

Hyperkalemia

ANG2 present

20
Q

What is the action of aldosterone?

A

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

Increased K secretion

21
Q

What are drug targets in the RAAS?

A
ACE inhibitors
ARB's (ang recep blockers) (antagonist)
Aldosterone antagonists
Ca channel blockers
Diuretics
Beta blockers
22
Q

Whats an example of an ACE inhibitor?

A

Ciliazipril

23
Q

How do ACE inhibitors work?

A

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

24
Q

What is the dual effect of ACE inhibitors?

A

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
Q

What is angioedema?

A

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

26
Q

What is an example of an ARB?

A

Losartan

27
Q

What sort of action does an ARBs have?

A

Competitive reversible antagonist at AT1

28
Q

Which should be used ARB or ACE inhibitors?

A

ACE inhibitors are generally more effect.

A combination causes renal damage.

ARB used as substitute for ARB’s

29
Q

How would you block aldosterone action?

A

Aldosterone antagonists

30
Q

Whats an example of an aldosterone antagonist?

A

Spirinolactone

31
Q

What does spirinolactone do?

A

Prevents Na reabsorption caused by aldosterone

32
Q

How do calcium channel blockers work?

A

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

33
Q

Whats an example of a Ca channel blocker?

A

Verapamil

34
Q

What do diuretics do?

A

Oppose ANG2 effects

35
Q

What is the function of a diuretic primarily/

A

increases na excretion

36
Q

Whats an example of a diuretic?

A

Amilorides

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

37
Q

How do beta blockers work?

A

Competitive antagonists at b adrenergic receptors

primarily B1

38
Q

What does B blocker use result in?

A

Decreased contractility

Decreased Renin secretion

39
Q

Whats an example of a Beta blocker?

A

Metoprolol

40
Q

What are three types or diuretics?

A

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