Trachte Adrenergic Agonists

Question 1

Relate HR, TPR, SV and BP

Answer 1

BP = HR x SV x TPR

Question 2

Stepwise synthesis of NE:

Answer 2

Tyrosine –> DOPA –> Dopamine –> NE –> Epi (in adrenal medula)

Question 3

Cholinergic receptors in Heart and vessels:

Which nerve acts on them?

Answer 3

Muscarinic (M2)

Vagus (pre-ganglionic; Ach on Nicotinic R)

Parasympathetic

Question 4

Adrenergic receptors on heart and vessels:

NT and R for ganglia synapse?

Answer 4

Beta1 (NE)– Heart

alpha 1 (NE)– vessels

Ach, Nicotinic

Sympathetic

Question 5

Cholinergic receptors on sweat glands: NT?

Answer 5

M2, Ach

(ganglia is Ach, Nic)

Sympathetic

Question 6

Sympathetic NT and receptor of renal vessels:

Answer 6

Dopamine, D1

ganglia is Ach –> Nic

Question 7

NT’s in the blood that act on Beta 1’s and alpha 1’s in the heart and vessels:

Where do they come from?

Answer 7

Epi

NE

Adrenal medula (sympathetic response via preganglionic neuron Ach on Nicotic R in the medula)

Question 8

Inhibits axoplasmic pump to potentiate sympathetic response:

Answer 8

Cocaine

Question 9

Inhibits granular pump accumulating catecholamines in vesicles (results in depletion of catecholamines):

Answer 9

Respirine

Question 10

Induces release of NE from vesicles –> depletes NE stores –> reduces response to sympathetic stimulation

**inactive in the presence of MOA inhibitors like Pargyline

Answer 10

Guanethidine

Question 11

Two enzymes that degrade adrenergic amines:

Answer 11

COMT (cytoplasm)

MAO (mitochondria)

Question 12

MAO inhibitor:

Patients taking this should avoid what?

Answer 12

pargyline

foods high in tyramine

Question 13

a1 receptor

primary CV location:

relative response to NT’s:

MOA:

Answer 13

blood vessels

epi >/= NE&raquo_space; isoproterenol

activates phospholipase C (Gq protein rec.) –> inc. intracellular Ca2+ via IP3

**mediates smooth muscle CONTRACTION

Question 14

Beta 1 receptor

locations:

relative response to NTs:

MOA:

Answer 14

adrenergic cardiac effects, renin release

heart, JG apparatus and adipose tissue

isoproterenol > epi = NE

acts to increase cAMP via Gs

Question 15

Beta 2 receptor

locations:

relative response to NTs:

MOA:

Answer 15

relaxation of smooth muscle and glycogenolytic effects

vascular smooth muscle

isoproterenol > epinephrine&raquo_space; NE

increase cAMP via Gs

Question 16

Selective B1 agonist

positive inotrope (increases muscular cont.)

Answer 16

Dobutamine

Question 17

• positive inotrope at B1
• vasodilator in renal and mesentary at low doses (dopaminergic)
• vasoconstrictor at a1 at high doses

used in shock (maintains renal perfusion) and hypotension (inc. BP and CO)

Answer 17

Dopamine

Question 18

a1 agonist

used to reverse hypotension or treat paroxysmal atrial tachycardia

also used as mydriatic and topical vasoconstrictor

Answer 18

Phenylepherine

Question 19

B2 selective agonists used for bronchodilation (3):

Answer 19

Metaproterenol

Albuterol

Salmeterol

Question 20

B2 selective agonists used to delay labor (2):

Answer 20

ritodrine

terbutaline

Question 21

vasodilates at B2

tachycardia at B1

metabolised by COMT but not MAO

synthetic catecholamine

Answer 21

Isoproterenol

Question 22

Vasoconstricts at a1

increases HR and force at B1

used to treat hypotension

Answer 22

Norepinephrine

Question 23

Vasoconstricts a1

vasodilates B2

inc. HR

used in anaphylaxis to treat bronchospasm and hypotension

Answer 23

Epinephrine