Question

6.              Which of the following is the α1 drug of choice for retinal exams and surgery, giving mydiasis (dilation of iris)?

a) Ephedrine

b) Epinepherine

c) Oymetazoline

d) Isoproterenol

e) Phenylephrine

7.              At the adrenergic synapse, what does α2 do?

a) Stimulates NE release

b) Inhibits NE release

c) Stimulates ACh release

d) Inhibits ACh release

8.              Carbidopa is a   

a) MAO type B inhibitor

b) COMT inhibitor

c) Dopacarboxylase inhibitor

d) Dopamine agonist

e) none of the above

9.               ___________ and _____________ are selective a and b blockers, respectively.   

a)    Ep and Nor E

b)    NorE and Ep

c)     IsoP and NorE

d)    NorE and IsoP

Answer 1

Ans 6 (e) Phenylepherine

Explanation:

Phenylephrine is used to dilate the iris through alpha-adrenergic stimulation of the iris dilator muscle. It is given as eye drops to dilate the iris before eye surgery or eye examinations.

7. (a) stimulate NA release

Explanation:

The α2-adrenergic receptor binds both norepinephrine released by sympathetic postganglionic fibers.

8. (c) Dopacarboxylase inhibitor

Explanation:

Carbidopa inhibits aromatic-L-amino-acid decarboxylase (DOPA decarboxylase). It is an enzyme important in the biosynthesis of L-tryptophan to serotonin and in the biosynthesis of L-DOPA to dopamine. DOPA decarboxylase exists both outside of (body periphery) and within the confines of the blood–brain barrier.

9. (d) NorE and IsoP

Explanation:

Norepinephrine and isopernaline are respective alpha and beta receptor agonists.