Adrenergic Agonists Flashcards

1
Q

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

A

Catecholamines

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2
Q

alpha or beta receptors. lipid soluble. maybe orally administered

A

Non-catecholamines

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3
Q

What kind of uptake via NET? Uptake 1.

A

Neuronal

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4
Q

Uptake 2 is what kind of uptake?

A

Extra-neuronal

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5
Q

Which catecholamine(s) are removed by uptake 1?

A

NE

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6
Q

Which catecholamine(s) are removed via uptake 2?

A

Epi and Isoproterenol

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7
Q

Final product of MAO/COMT degradation?

A

MHGP

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8
Q

MHGP is converted mostly to:

A

VMA

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9
Q

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

A

Pheochromocytoma

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10
Q

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

A

MAO

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11
Q

Example of MAO inhibitor

A

Pargyline

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12
Q

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

A

COMT

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13
Q

Where can COMT be found?

A

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

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14
Q

Action of catecholamines and sympathomimetics on alpha 1 receptor

A

Peripheral excitatory on smooth muscles:

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

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15
Q

Action of catecholamines and sympathomimetics on beta 2

A

Peripheral inhibitory:

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

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16
Q

Action of catecholamines and sympathomimetics on beta 1

A

Positive chronotropy, inotropy, dromotropy

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17
Q

Action of catecholamines and sympathomimetics on beta 3

A

Mobilization of energy stores: Increased glucose and free fatty acids

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18
Q

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

A

Beta receptor.

Increases glucagon.

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19
Q

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

A

Beta 2 receptor: increases insulin.

Alpha 2 receptor: inhibition of insulin, induces glucagon

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20
Q

Effect of epinephrine on insulin?

A

inhibition via alpha 2 activation

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21
Q

Action of catecholamines and sympathomimetics on JG cells?

A
alpha 2: inhibits renin secretion
beta 1 (& 2): enhances renin secretion
22
Q

Action of catecholamines and sympathomimetics on CNS?

A

increases wakefulness (amphets) and suppress appetite

23
Q

Action of catecholamines and sympathomimetics on pre-synaptic?

A

modulate NT release. inhibition by alpha 2 more important!

24
Q

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

A

bladder neck, prostate

Gq

25
Q

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

A

blood vessels

Gi (inhibition of adenlyl cyclase results in vasodilation)

26
Q

Beta 1 GPCR class?

A

Gs

27
Q

Beta 2 GPCR class?

A

Gs

28
Q

Where are D1 receptors found? GPCR class?

A

renal, mesenteric, splanchnic, coronary, cerebral.

Gs

29
Q

D5 receptors are similar to

A

D1 receptors

30
Q

D2-4 receptors GPCR class?

A

Gi

31
Q

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

A

homologous desensitization

32
Q

Broad unresponsiveness of receptor due to a different agonist:

A

heterologous desensitization

33
Q

Parent compound of sympathomimeics

A

phenylethylamine

34
Q

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

A

reduced potency. phenylephrine

35
Q

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

A

results in isopropylamines. ephedrine, aphetamine

36
Q

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

A

results in catecholamines

37
Q

Substitution of amino group of phenylethylamine with METHYL?

A

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

38
Q

Substitution of amino groups of phenylethylamine with ISOPROPYL?

A

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

39
Q

Substitution of alpha carbon of phenylethylamine?

A

results in ephedrine, amphetamines.

BLOCKS MAO oxidation (prolonged effect). ability to displace catecholamines.

40
Q

Substitution of beta carbon of phenylethylamine?

A

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

41
Q

Effects of small dose of E?

A

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

42
Q

Effects of large dose of E?

A

INCREASE in BP due to increase heart rate/contractility.

43
Q

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

A

biphasic response.
alpha 1: vasoconstriction
beta 2: vasodilation

44
Q

Epinephrine on metabolism:

A

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

45
Q

Epinephrine on CNS:

A

Nervousness, awareness of danger, restlessness, termors

46
Q

Epinephrine on respiratory:

A

Bronchidilation (Beta 2)

Decreased bronchial secretion (alpha)

47
Q

Epinephrine on uterus:

A

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

48
Q

Norepinephrine on uterus:

A

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

49
Q

Epinephrine on urogenital:

A

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

50
Q

Epinephrine + nonselective beta blocker:

A

alpha 1 unopposed –> increased TPR –> increased BP