A.8

Question 1

Adrenergic transmission and its presynaptic modification

Answer 1

Levodopa,
Carbidopa

Question 2

Levodopa, Carbidopa

Answer 2

IND: Parkinson’s disease;
MOA: Metabolic precursor of dopamine;
ROA: p.o; Effect: can cross BBB, ↑synthesis of DA. ; DOA: 6-8h;
SEs: GI distress, Dyskinesia, Hypotention, arrhythmias, psychosis, agitation
note: Levodopa increases the synthesis of Dopamine
Levodopa is converted by DOPA-decarboxylase → only 1-3% enters the brain due to extensive peripheral metabolism by the enzyme → give Carbidopa which is a peripheral inhibitor of the enzyme

Question 3

Effects of sympathetic system on organs

Answer 3

Eye: mydriasis (α1), aqueous humor production↑ (β2), lacrimation (α)
Bronchial smooth muscle: Bronchodilation (β2)
Bronchial glands: secretions↓ (α1), secretions↑(β2)
GI tract: GI motility↓ (α1,β2), constriction of sphincters (α1), inhibition of secretion (α2)
Liver and gallbladder: glycogenolysis and gluconeogenesis (α1 and β2), relaxation of gallbladder (β2)
Uterus: relaxation (β2)
Urinary bladder: detrusor tone↓ (β2/3)
Blood vessels: constriction (α1), dilation (β2)
Heart: + inotropic, chronotropic, dromotropic (β1»β2
Male sexual organ: Ejaculation

Question 4

influence adrenergic transmission

Answer 4

1. Presynaptic stimulation
2. Presynaptic inhibition
3. postsynaptic stimulation
4. postsynaptic inhibition