Adrenergic Pharmacology

Question 1

What catalyzes the conversion of l-DOPA to Dopamine?

A. Tyrosine hydroxylase

B. DOPA decarboxylase (AAADC)

C. Dopamine B-hydroxylase

D. Phenylethanolamine N-methyltransferase

Answer 1

B - aromatic l-amino acid decarboxylase (AAADC) catalyzes conversion

Question 2

What inhibits the synthesis of l-DOPA to dopamine?

A. Carbidopa

B. tyrosine hydroxylase

C. a-methyltyrosine

D. a-methyldopa

Answer 2

A

Question 3

______________ is used for pre-operative reduction of catecholamine synthesis in pheochromocytoma, a neuroendocrine tumor of the medulla.

A. Carbidopa

B. tyrosine hydroxylase

C. a-methyltyrosine

D. a-methyldopa

Answer 3

C - a-methyl tyrosine is a synthetic analog of tyrosine that inhibits tyrosine hydroxylase

Question 4

_______ is a synthetic analog of tyrosine that inhibits tyrosine hydroxylase.

A. Carbidopa

B. DOPA decarboxylase

C. a-methyltyrosine

D. a-methyldopa

Answer 4

C

Question 5

During autoregulation of neurotransmission, stimulation of ______________ adrenergic receptors inhibits norepinephrine release.

A. pre-synaptic a2

B. post-synaptic a2

C. pre-synaptic a1

D. pre-synaptic B2

E. post-synaptic B2

Answer 5

A

Question 6

During autoregulation of neurotransmission, stimulation of ______________ adrenergic receptors potentiates norepinephrine release.

A. pre-synaptic a2

B. post-synaptic a2

C. pre-synaptic a1

D. pre-synaptic B2

E. post-synaptic B2

Answer 6

D

Question 7

If a large amount of norepinephrine is released into the bloodstream, NE may act on distant effect cells. NE spillover is __________ in congestive heart failure.

A. increases

B. unchanged

C. decreases

Answer 7

A

Question 8

What two types of drugs inhibit neuronal uptake of norepinephrine?

Answer 8

1. Cocaine
2. Tricyclic antidepressants

Question 9

Active transport of norepinephrine through th emembrane by other tissues/organs/transporters is inhibited by ____________.

Answer 9

steroid hormones/corticosterone

Question 10

The major metabolite from the final metabolic disposition of catecholamines is ____________.

Answer 10

vanillylmandelic acid

Question 11

a-Methyldopa is a ___________ that functions as an anti-hypertensive.

A. presynaptic a1 agonist

B. presynaptic a2 agonist

C. postsynaptic a1 agonist

D. presynpatic a1 antagonist

E. postsynaptic a2 antagonist

Answer 11

B - a2 reduces central sympathetic outflow as an a2 agonist “false neurotransmitter”

Question 12

Which functions to deplete NE from adrenergic terminals via inhibition of transporter systems of storage vesicles?

A. Bretilium

B. Guanethidine

C. Reserpine

D. Cocaine

E. a-methyldopa

Answer 12

C - resepine promots depletion and destruction of NE.

Question 13

Which causes accumulation of NE at the receptor site due to inhibition of NE re-uptake?

A. Cocaine

B. TCAs

C. Bretilium

D. Guanethidine

E. A and B

F. C and D

Answer 13

E

Question 14

Which drugs function to replace NE in vesicles and prevent norepinephrine release from storage vesicles?

A. Cocaine

B. TCAs

C. Bretilium

D. Guanethidine

E. A and B

F. C and D

Answer 14

F

Question 15

a2 post-synaptic adrenergic receptors are located elsewhere on the vascular muscle cells and activated mainly by circulating catecholamines, but predominantly __________.

A. Epinephrine

B. Norepinephrine

C. Dopamine

D. None of these

Answer 15

A

Question 16

__________ receptors are located close to the site of NE release and are mainly responsible for neuronal NE mediated vasoconstriction of smooth muscle.

A. a1 presynaptic

B. a1 postsynaptic

C. a2 presynaptic

D. a2 postsynaptic

Answer 16

B

Question 17

Vasoconstriction in the skin and splanchnic vascular beds (and large arteries/veins) is mediated by ______________ adrenergic receptor stimulation.

A. a1 presynaptic

B. a1 postsynaptic

C. a2 presynaptic

D. a2 postsynaptic

Answer 17

B

Question 18

Activation of ____________ receptors in the vasomotor center has a sympathoinhibitory effect to reduce central sympathetic outflow and vasomotor tone (i.e. reduced blood pressure and heart rate, reduced renin release).

A. a1 presynaptic

B. a1 postsynaptic

C. a2 presynaptic

D. a2 postsynaptic

Answer 18

C

Question 19

Activation of ______________ adrenergic receptors in the sympathetic nerve endings inhibits norepinephrine release.

A. a1 presynaptic

B. a1 postsynaptic

C. a2 presynaptic

D. a2 postsynaptic

Answer 19

C

Question 20

Stimulation of ___________ adrenergic receptors in the kidney induces renin release.

A. a1

B. a2

C. B1

D. B2

Answer 20

C

Question 21

Stimulation of ________________ adrenergic receptors causes relaxation of most types of smooth muscle.

A. B1 presynaptic

B. B2 presynpatic

C. B1 postsynaptic

D. B2 postsynaptic

Answer 21

D

Question 22

Stimulation of ___________ receptors increases NE release from sympathetic nerve endings.

A. B1 presynaptic

B. B2 presynpatic

C. B1 postsynaptic

D. B2 postsynaptic

Answer 22

B

Question 23

Which receptors stimulate insulin secretion in the pancreas and thereby increase glucose uptake in skeletal muscles?

A. B1 presynaptic

B. B2 presynpatic

C. B1 postsynaptic

D. B2 postsynaptic

Answer 23

D

Question 24

The B1 adrenergic receptor causes:

A. relaxation of bronchial smooth muscle

B. increases in glycogenolysis in skeletal muscle

C. contraction of radial muscle in the eye

D. increases in renin release in the kidney

Answer 24

D

Question 25

The B2 adrenergic receptor causes: A. relaxation of bronchial smooth muscle B. decreases in glycogenolysis in skeletal muscle C. contraction of radial muscle in the eye D. increases in renin release in the kidney

Answer 25

A

Question 26

The a1 adrenergic receptor causes: A. relaxation of bronchial smooth muscle B. increases in glycogenolysis in skeletal muscle C. contraction of radial muscle in the eye D. increases in renin release in the kidney

Answer 26

C

Question 27

Norepinephrine has the highest affinity for which receptor?

Answer 27

B1 (\>a1\>a2)

Question 28

\_\_\_\_\_\_\_\_\_\_\_\_ is a drug of choice for anaphylactic shock.

Answer 28

Epinephrine

Question 29

At high doses, dopamine activates the a1 receptor and has the following effect: A. Decreases renal and splanchnic blood flow B. Increases cardiac contractility C. Increases splanchnic and renal blood flow D. Increases cerebral and coronary blood flow

Answer 29

A - marked tachycardia may occur with high doses of DA

Question 30

Uncontrolled hypertension that is paroxysmal in nature (during adrenergic crisis) is indicative of \_\_\_\_\_\_\_\_\_\_\_\_.

Answer 30

Pheochromocytoma (shown by VMA levels in the urine)

Question 31

A mid-level dose of dopamine will have the following effect: A. activation of B1 receptor B. increases cardiac contractility C. no effect on BP/HR D. All of the above result from mid-level DA doses

Answer 31

D

Question 32

In heart failure, responsiveness to B-adrenergic stimulation in suppressed, mainly because of \_\_\_\_\_\_\_\_\_\_\_.

Answer 32

downregulation of the B1-adrenergic receptor

Question 33

Ephedrine is classified as: A. non-selective direct-acting sympathomimetic B. selective direct-acting sympathomimetic C. indirect-acting sympathomimetic D. mixed-acting sympathomimetic

Answer 33

D

Question 34

Which two drugs are adrenergic agonists that are not sympathomimetics?

Answer 34

Clonidine and a-methyl DOPA are adrenergic agonists that have sympathoinhibitory effects

Question 35

MAO and COMT inhibitors are ________ drugs. A. non-selective direct-acting sympathomimetic B. selective direct-acting sympathomimetic C. indirect-acting sympathomimetic D. mixed-acting sympathomimetic

Answer 35

C

Question 36

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ act pre-synaptically to increase catecholamine availability. ## Footnote A. non-selective direct-acting sympathomimetic drugs B. selective direct-acting sympathomimetic drugs C. indirect-acting sympathomimetic drugs D. mixed-acting sympathomimetic drugs

Answer 36

C

Question 37

\_\_\_\_\_\_\_\_\_\_\_ release norepinephrine and act directly on adrenergic receptors. ## Footnote A. non-selective direct-acting sympathomimetic drugs B. selective direct-acting sympathomimetic drugs C. indirect-acting sympathomimetic drugs D. mixed-acting sympathomimetic drugs

Answer 37

D

Question 38

Central sympatholytic drugs are also known as agonists of what receptor?

Answer 38

presynaptic a-2 agonists

Question 39

Why should beta blockers be used cautiously in diabetics?

Answer 39

They can mask the tachycardia that serves as a warning sign for insulin induced hypoglycemia.

Question 40

Which drug is NOT an inhibitor of adrenergic nerve terminals? A. Reserpine B. Guanethidine C. Clonidine D. Guanabenz

Answer 40

C - Clonidine and a-methyldopa (not listed) are sympatholytic drugs taht stimulate central a2 adrenergic receptors in the medulla.