Adrenergic Agonists

Question 1

alpha or beta receptor activation. inactiv by COMT or MAO. poor oral abs. cannot readily cross BBB.

Answer 1

Catecholamines

Question 2

alpha or beta receptors. lipid soluble. maybe orally administered

Answer 2

Non-catecholamines

Question 3

What kind of uptake via NET? Uptake 1.

Answer 3

Neuronal

Question 4

Uptake 2 is what kind of uptake?

Answer 4

Extra-neuronal

Question 5

Which catecholamine(s) are removed by uptake 1?

Answer 5

NE

Question 6

Which catecholamine(s) are removed via uptake 2?

Answer 6

Epi and Isoproterenol

Question 7

Final product of MAO/COMT degradation?

Answer 7

MHGP

Question 8

MHGP is converted mostly to:

Answer 8

VMA

Question 9

Increased levels of catecholamines and its metabolites in urine could indicate:

Answer 9

Pheochromocytoma

Question 10

Bound to surface membrane of mitochondria. Present in liver and intestinal epithelium. Converts catecholamines and other monoamines.

Answer 10

MAO

Question 11

Example of MAO inhibitor

Answer 11

Pargyline

Question 12

Acts through methylation of catechol-OH group into a methoxy derivative.

Answer 12

COMT

Question 13

Where can COMT be found?

Answer 13

Adrenal medulla and other cells and tissues. Not found in noradrenergic neurons.

Question 14

Action of catecholamines and sympathomimetics on alpha 1 receptor

Answer 14

Peripheral excitatory on smooth muscles:

vasoconstriction, goosebumps, contraction of radial muscles of iris (mydriasis)

Question 15

Action of catecholamines and sympathomimetics on beta 2

Answer 15

Peripheral inhibitory:

relaxation of detrusor ms (prevents voiding), bronchial ms, GIT ms.

Question 16

Action of catecholamines and sympathomimetics on beta 1

Answer 16

Positive chronotropy, inotropy, dromotropy

Question 17

Action of catecholamines and sympathomimetics on beta 3

Answer 17

Mobilization of energy stores: Increased glucose and free fatty acids

Question 18

Action of catecholamines and sympathomimetics on pancreatic alpha cells (which type of adrenergic receptor?)

Answer 18

Beta receptor.

Increases glucagon.

Question 19

Action of catecholamines and sympathomimetics on pancreatic beta cells (which type of adrenergic receptor?)

Answer 19

Beta 2 receptor: increases insulin.

Alpha 2 receptor: inhibition of insulin, induces glucagon

Question 20

Effect of epinephrine on insulin?

Answer 20

inhibition via alpha 2 activation

Question 21

Action of catecholamines and sympathomimetics on JG cells?

Answer 21

alpha 2: inhibits renin secretion
beta 1 (& 2): enhances renin secretion

Question 22

Action of catecholamines and sympathomimetics on CNS?

Answer 22

increases wakefulness (amphets) and suppress appetite

Question 23

Action of catecholamines and sympathomimetics on pre-synaptic?

Answer 23

modulate NT release. inhibition by alpha 2 more important!

Question 24

Where are alpha 1A receptors found? What is the GPCR class?

Answer 24

bladder neck, prostate

Gq

Question 25

Where are alpha 1B receptors found? What is the GPCR class?

Answer 25

blood vessels | Gi (inhibition of adenlyl cyclase results in vasodilation)

Question 26

Beta 1 GPCR class?

Answer 26

Gs

Question 27

Beta 2 GPCR class?

Answer 27

Gs

Question 28

Where are D1 receptors found? GPCR class?

Answer 28

renal, mesenteric, splanchnic, coronary, cerebral. | Gs

Question 29

D5 receptors are similar to

Answer 29

D1 receptors

Question 30

D2-4 receptors GPCR class?

Answer 30

Gi

Question 31

A decrease in receptor response via uncoupling of the receptor due to prolonged, high concentrations of agonist:

Answer 31

homologous desensitization

Question 32

Broad unresponsiveness of receptor due to a different agonist:

Answer 32

heterologous desensitization

Question 33

Parent compound of sympathomimeics

Answer 33

phenylethylamine

Question 34

Substitution by -OH groups at C3 and C4 of phenylethylamine: absence of one or the other -OH group?

Answer 34

reduced potency. phenylephrine

Question 35

Substitution by -OH groups at C3 and C4 of phenylethylamine: absence of both -OH groups?

Answer 35

results in isopropylamines. ephedrine, aphetamine

Question 36

Substitution by -OH groups at C3 and C4 of phenylethylamine?

Answer 36

results in catecholamines

Question 37

Substitution of amino group of phenylethylamine with METHYL?

Answer 37

results in epinephrine. increased B receptor activity(lower alpha)

Question 38

Substitution of amino groups of phenylethylamine with ISOPROPYL?

Answer 38

results in isoproterenol. increased beta receptor activity (no effect on alpha)

Question 39

Substitution of alpha carbon of phenylethylamine?

Answer 39

results in ephedrine, amphetamines. | BLOCKS MAO oxidation (prolonged effect). ability to displace catecholamines.

Question 40

Substitution of beta carbon of phenylethylamine?

Answer 40

NE, E, isoproterenol all have -OH at beta carbon. Facilitates storage of NT in vesicles.

Question 41

Effects of small dose of E?

Answer 41

DECREASE in BP due to greater sensitivity of vascular beta 2(vasodilation -> decreased PVR). No increase in HR or contractility yet.

Question 42

Effects of large dose of E?

Answer 42

INCREASE in BP due to increase heart rate/contractility.

Question 43

Dual stimulation of alpha 1 and beta 2 receptors in vasculature result in

Answer 43

biphasic response. alpha 1: vasoconstriction beta 2: vasodilation

Question 44

Epinephrine on metabolism:

Answer 44

glycogenolysis, lipolysis, gluconeogenesis, decreased uptake of glucose in peripheral tissues.

Question 45

Epinephrine on CNS:

Answer 45

Nervousness, awareness of danger, restlessness, termors

Question 46

Epinephrine on respiratory:

Answer 46

Bronchidilation (Beta 2) | Decreased bronchial secretion (alpha)

Question 47

Epinephrine on uterus:

Answer 47

Inhibits uterine tone and contraction during last month of pregnancy. Beta 2 agonits at parturition can delay premature labor

Question 48

Norepinephrine on uterus:

Answer 48

No beta 2 action --> alpha 1 stimulation --> uterine contraction

Question 49

Epinephrine on urogenital:

Answer 49

Relaxes detrusor muscle (beta 2) resulting in urinary retention.

Question 50

Epinephrine + nonselective beta blocker:

Answer 50

alpha 1 unopposed --> increased TPR --> increased BP