Adrenergic receptors

Question 1

adrenaline and noradrenaline are

Answer 1

catecholamines

Question 2

noradrenaline is the main

Answer 2

NT of the sympathetic nerves in cardiovascular system

Question 3

adrenaline is

Answer 3

the main hormone secreted by the adrenal medulla

Question 4

adrenoreceptors are located

Answer 4

throughout the body on neuronal and non-neuronal tissue

Question 5

adrenoreceptors are

Answer 5

GPCR’s

Question 6

binding of catecholamines to the receptor is responsible for

Answer 6

fight or flight response

Question 7

name the types of adrenoreceptors

Answer 7

alpha1, alpha2, beta1, beta2, beta3

Question 8

alpha1

Answer 8

o Vascular smooth muscle
o Visceral smooth muscle
o CNS neurone

Question 9

alpha2

Answer 9

o	Presynaptic terminals
o	Pancreatic islets
o	Platelets
o	Ciliary epithelium
o	Smooth muscle
CNS neurones

Question 10

beta1

Answer 10

o Myocardium (heart)
o JG cells
o Some presynaptic terminal
CNS neurons

Question 11

beta2

Answer 11

o	Visceral (guts) smooth muscle
o	Vascular smooth muscle (bronchi)
o	Liver
o	Urinary tract
o	Myocardium
Skeletal

Question 12

beta3

Answer 12

adipose tissue

Question 13

alpha1 adrenoreceptors are coupled with

Answer 13

Gq
α1 adrenergic receptors (Gq)
1) Adrenaline binds to GPCR
2) Gq activates phospholipase C, which hydrolyses PIP2 IP3 and DAG
3) Increase in IP3 and therefore increase in calcium
4) Calcium binds to calmodulin and activates MLCK, which causes myosin heads to form cross-bridges- contraction
5) Activation of enzyme protein kinase C (PKC) by DAG
6) Phosphorylation of other enzyme
7) Increase or decrease of electrolyte transfer in or out of the cell

Question 14

when alpha1 blocker is added

Answer 14

hypertension treatment- since cascade does not occur

Question 15

alpha2 adrenoreceptor linked with

Answer 15

Gi

1) Substrate (adrenaline) binds to GPCR
2) Gi associates with adenylyl cyclase
3) Decrease in CAMP
4) PKA is not activated by cAMP
5) Proteins such as PK cannot be phosphorylated by PKA
6) No activation of glycogen phosphorylase
7) Decreased breakdown of glycogen

Question 16

when alpha2 blocker is added

Answer 16

hypertension treatment

Question 17

B1 adrenoreceptors linked with

Answer 17

Gs

1) Activates adenylate cyclase
2) Increase in cAMP

Question 18

B2 adrenoreceptors linked with

Answer 18

Gs

1) Channel complex is coupled to the GsG protein
2) Activates adenylyl cyclase
3) Formation of cAMP
4) Activates pKA

Question 19

alpha 1 adreno receptors cause

Answer 19

vasoconstriction, increase in BP

Question 20

alpha 2 adrenorecepors cause

Answer 20

vasodilation of blood vessels and inhibitor pf NA, Ach and insulin release

Question 21

Beta1 receptors

Answer 21

increase cardiac output by increasing heart rate and contractility
- increased renin secretion

Question 22

Beta2 receptors

Answer 22

smooth muscle relaxation (lungs)

Question 23

Beta3 receptors

Answer 23

lipolysis in adipose