ANG Receptors in BP

Question 1

What 3 things does the renin-angiotensin system regulate?

Answer 1

body fluid volume
electrolyte balance
arterial pressure (MAP)

Question 2

What are the 3 types of RAS system?

Answer 2

classical circulating
tissue/local
intracellular

Question 3

Where is every protein of RAS produced?

Answer 3

Proximal tubule of kidney

Question 4

What does ANGII bind to?

Answer 4

AT-1

Question 5

What happens in severe haemorrhage?

Answer 5

Blood volume decreases -> BP falls -> perfusion of tissues reduced

Question 6

How do the kidneys respond to haemorrhage?

Answer 6

Increased production of renin by granular cells of afferent arterioles

Question 7

What does increased renin cause?

Answer 7

Angiotensinogen is converted into AT-1

Question 8

What does AT-1 cause?

Answer 8

Converted into AT-2 via ACE in the endothelium of lungs and capillaries

Question 9

What does AT-2 bind?

Answer 9

AT1 receptor of target organ

Question 10

What are 4 ANG-2 functions?

Answer 10

Vasoconstriction
Aldosterone secretion
Sodium and water reabsorption
Vasopressin release

Question 11

What happens when AT2 levels increase?

Answer 11

-ve feedback loop -> decrease renin production

Question 12

What 4 things does ANGII constrict?

Answer 12

arterial and venous smooth muscle
pre arcuate and interlobular arteries
post glomerular resistance vessels
glomerular mesangial cells

Question 13

What 3 places does ANGII increase Na+ reabsoprtion?

Answer 13

tubular
PCT via Na+H+ exchange
distal tubules in principal cells of CD (aldosterone release)

Question 14

What is AT2 rapidly degraded into?

Answer 14

AT3 and AT4

Question 15

What AT receptors does ACE-2 interact with?

Answer 15

AT1-7 which binds to the Mas receptor and causes vasodilation

Question 16

Does the AT2 receptor cause vasoconstriction?

Answer 16

no - vasodilation

Question 17

What does AT2 have increased expression?

Answer 17

In disease

Question 18

In the adult kidney where are AT2Rs expressed?

Answer 18

primarily in renal proximal tubule

Question 19

How does AT2 induce vasodilation and natriuresis

Answer 19

By raising BK and NO which increases cGMP

Question 20

What rad model was looked at for AT2R?

Answer 20

Sprague-dawley rat was treated with the AT2R agonist (C-21)

Question 21

Which molecule has an increased excretion rate with AT2R activation/

Answer 21

Sodium

Question 22

How is natriuresis induced when C-21 activates AT2Rs?

Answer 22

In a bradykinin, NO and cGMP dependent manner

Question 23

Where do AT2R receptors migrate to upon C-21 infusion?

Answer 23

apical membrane of PT

Question 24

What does AT2Rs internalize?

Answer 24

NHE-3 which induces natiuresis

Question 25

When does AT2R lower BP?

Answer 25

in ANG-II dependent hypertension