Catecholamines

Front 1

Pre- and postganglionic neurotransmitters of the parasympathetic nervous system?

Back 1

Acetylcholine for both

Front 2

Pre- and postganglionic neurotransmitters of the sympathetic nervous system?

Back 2

preganglionic: acetylcholine
postganglionic: catecholamines (NE, E, DA) EXCEPT sweat glands (use ACh)

Front 3

Functions of the sympathetic nervous system (5)?

Back 3

1) regulate heart rate and contractility
2) regulate blood vessel constriction
3) regulate smooth muscle contraction
4)regulate secretory processes
5) regulate carbohydrate and fat metabolism

Front 4

Precursor of the catecholamines?

Back 4

Tyrosine

Front 5

Rate-limiting step of catecholamine synthesis?

Back 5

Tyrosine hydroxylase

Front 6

Where does synthesis of catecholamines take place?

Back 6

Dopamine: in the cytoplasm of nerve cells
NE and Epi: in synaptic vesicles of nerve endings

Front 7

How are catecholamines stored (2)?

Back 7

1) Vesicles: VMAT= uptake pump
2) adrenal medulla (chromaffin granules)

Front 8

How is catecholamine release achieved and regulated?

Back 8

1) Release is Ca2 dependent
2) regulated by interaction with pre-synaptic receptors (a2=negative feedback; B=positive feedback)

Front 9

Methods of inactivation (3)

Back 9

1) re-uptake
2) metabolism
3) diffusion and re-uptake at extra-neuronal site

Front 10

Methods of re-uptake (2)

Back 10

1) re-uptake into nerve ending; specific, high affinity, low capacity
2) re-uptake into extra-neuronal site; not specific, low affinity, high capacity

Front 11

Methods of transformation/catabolism (2)

Back 11

1) MAO; type A=NE, Epi; type B=DA
2) other degradative enzymes: COMT, aldehyde reductase, aldehyde dehyrdrogenase

Front 12

Adrenergic receptors: Alpha 1

Back 12

Subunit: Gq
Binds: NE, Epi
Second msgr: PLC--> increase free Ca2

Front 13

Adrenergic receptors: Alpha 2

Back 13

Subunit :Gi
Binds: NE, Epi
Second msgr: AC-->decrease cAMP

Front 14

Adrenergic Receptors: Beta 1

Back 14

Subunit: Gs
Binds: NE, Epi
Second msgr: AC-->increase cAMP

Front 15

Adrenergic Receptors: Beta 2

Back 15

Subunit: Gs
Binds: Epi
Second msgr: AC--> increase cAMP

Front 16

Factors determining efficacy of sympathomimetic amines (4)

Back 16

1) potency
2) receptor density, proportion, subtypes
3) self-regulation of organism
4) refractoriness of receptor

Front 17

GPCR desensitization

Back 17

GSKs phosphorylate serine residues in GPCR and recruit B-arrestins that interfere with the G proteins interaction with its subunit

Front 18

a-methyl-p-tyrosine

Back 18

inhibit tyrosine hydroxylase (no clinical usage)

Front 19

a-methyldopa

Back 19

inhibit L-AAD and block receptos

Front 20

carbidopa

Back 20

inhibit L-AAD in periphery

Front 21

tetraethylthiuram (Disulfam)

Back 21

inhibit dopamine B-hydroxylase; alcoholics use to induce averse response to drinking

Front 22

Reserpine

Back 22

Blocks VMAT

Front 23

Bretylium

Back 23

Prevent APs from reaching nerve ending--> no nt release

Front 24

Guanethidine

Back 24

inhibit release of NE

Front 25

Amphetamine and methamphetamine

Back 25

promote NT release

Front 26

cocaine

Back 26

inhibit reuptake of NE

Front 27

imipramine

Back 27

inhibit re-uptkae of NE and 5HT

Front 28

selegiline

Back 28

inhibit MAO-B--> delays breakdown of dopamine

Front 29

dobutamine

Back 29

agonist for dopamine; acts on B1 receptors to increase cardiac output (inotropic)

Front 30

l-dopa

Back 30

precursor to dopamine; administered with carbidopa to increase DA that reaches other side of BBB