Lecture 20: Intro to the Pharmacology of the ANS

Question 1

PNS Neurotransmitter

PNS receptors

Answer 1

Ach

mAchR, nAchR

Question 2

SNS Neurotransmitter

SNS receptors

Answer 2

NE,E,D,Ach

-a,B,D, nAchR, mAchR

Question 3

Ach is released in which places

Answer 3

All PNS postganglionic synapses
All preganglionic synapses
Some postganglionic sympathetic synapses

Question 4

NE is released in which places

Answer 4

Most postganglionic SNS synapses

Question 5

E is released in which places

Answer 5

Adrenal medulla mostly

Question 6

Dopamine acts on

Answer 6

Renal vascular smooth muscle

Question 7

How do you make Ach?

Answer 7

AcCoa + choline >chAT< Ach

Question 8

What degrades Ach in the synapse?

Answer 8

Acetylcholine esterase

Question 9

Ach binds to ______ in adrenal medulla triggering release of _________

Answer 9

nAchRs, catecholamines

Question 10

nAchR agonists

Answer 10

Ach and Nicotine

Question 11

M1, M2, M3 cholinergic receptors use which pathway and couples with what G protein?

Answer 11

PLC activation pathway, Gq

Question 12

M2, M4 cholinergic receptors use which pathway and couples with what G protein?

Answer 12

AC inhibition pathway, Gi

Question 13

How does NE get synthesized?

Answer 13

Cytoplasm: Tyr > Dopa > NE

Vesicle (of adrenal medullary cell): NE to Epi

Question 14

What does VMAT 2 do?

What does NET and DAT do?

Answer 14

Transports NE to vesicle

Reuptake of NE and Dopa into presynaptic neuron

Question 15

How is catecholamine signaling terminated?

Answer 15

• Main method is reuptake and recycling

- Minor method is metabolism by MAO and COMT at synapse

Question 16

Catecholamines bind _____ receptors

Answer 16

Adrenergic (a1,a2,b1,b2,b3, d1-5)

Question 17

A1 adrenergic receptors use which pathway and which G protein?
A2 adrenergic receptors use which pathway and which G protein?

Answer 17

• PLC pathway activation (Gq)

- AC pathway inhibition (Gi)

Question 18

B1-B3 receptors use which pathway and which G protein?

Answer 18

AC activation pathway (Gs)

Question 19

Which receptor prefers epinephrine?

Which receptor prefers NE?

Answer 19

B2

B3

Question 20

A1 and muscarinic adrenergic activation results in….

B2 adrenergic activation results in….

Answer 20

Smooth muscle contraction

Smooth muscle relaxation

Question 21

SNS causes ____ in heart, ____ in endothelium, and ______ in lungs/airways

Answer 21

Increased HR, contraction, relaxation/decreased mucus secretion

Question 22

PNS causes _____ in heart, _____ in endothelium, and _____ in lungs/airways

Answer 22

Decreased HR, vasodilation through NO synthase activation, contraction/increased mucus secretion

Question 23

What is required for the PNS to vasodilate the endothelium?

Answer 23

No PNS innervation to endothelium, but PNS activates NO/EDRF > causing vasodilation
-endothelium needs to be intact to vasodilate

Question 24

What is different about adrenal medulla ANS signaling?

Answer 24

Ach is released at post-synaptic terminal > binds to nAchRs on chromaffin cells > chromaffin cells release E

Question 25

How does the baroreceptor reflex relate to ANS signaling?

Answer 25

Senses what drugs are doing that stresses the system and tells ANS to override it

Example: drug vasoconstricting too much, reflex tells PNS to vasodilate it

Question 26

Cholinomimetic agents do what?

Cholinoceptor blocking drugs do what?

Answer 26

Act as AchR agonists and inhibit Acetylcholinesterase

Act as AchR antagonists

Question 27

Sympathomimetic agents do what?

Adrenoceptor blocking drugs do what?

Answer 27

• adrenergic agonists that enhance receptor stimulation

- adrenergic antagonists that decrease receptor stimulation