Erectile Dysfunction

Question 1

Erectile Dysfunction

Answer 1

Inability to achieve and maintain erection sufficient to permit sexual intercourse

Question 2

Viagra generic name

Answer 2

Oral sildenafil

Question 3

A rise in cytosolic calcium causes smooth muscle…

Answer 3

contraction

Question 4

Penile smooth muscle cytosolic calcium ______ during erection

Answer 4

Falls

Question 5

An ______ in cytosolic calcium leads to the binding of myosin to actin and the cross bridge cycling

Answer 5

Increase

Question 6

What is smooth muscle myosin’s regulatory light chain phosphorylated by?

Answer 6

Myosin light chain kinase

Question 7

What activates myosin light chain kinase?

Answer 7

Calmodulin-Ca complex

Question 8

When cytosolic Ca is elevated…

Answer 8

Ca forms complex with calmodulin

Question 9

Ca-calmodulin activates…

Answer 9

Myosin light chain kinase

Question 10

When cytosolic ca is low…

Answer 10

myosin phosphatase has a higher activity than myosin light chain kinase

Question 11

What dephosphorylates the light chain during penile relaxation?

Answer 11

Myosin phosphatase

Question 12

Control of smooth muscle contraction

Answer 12

1. Sympathetic stimulation (norepinephrine) activates receptors on SM cells.
2. Gq- protein activation increases IP3
3. IP3 stimulates Ca release from ER and entry of extracellular Ca through membrane channels
4. Rise in cytosolic Ca leads to contraction
5. Flaccid penis

Question 13

Control of smooth muscle relaxation

Answer 13

1. Parasympathetic stimulation (acetylchol.) activates endothelial receptors causing a release of NO
2. NO stimulates guanylyl cyclase increasing intracellular SM cGMP
3. Rise in cytosolic cGMP activates protein kinases causing a decrease in cytosolic Ca
4. Inactivation of MLCK
5. Erect penis

Question 14

Tumescence

Answer 14

Erect penis

Question 15

Detumescence

Answer 15

Flaccid penis

Question 16

While parasympathetic stimulation can activate endothelial receptors, it can inhibit…

Answer 16

sympathetic norepinephrine release (inhibiting contraction)

Question 17

How does PDE5 aid in killing a boner?

Answer 17

Hydrolyzes cGMP to 5’ -GMP allowing for more Ca and decreased cGMP

Question 18

How do PDE5 inhibitors work?

Answer 18

Inhibitors block hydrolysis of cGMP to 5’ -GMP causing lowered cytosolic Ca and relaxation

Question 19

Levitra generic name

Answer 19

Vardenafil

Question 20

Cialis generic name

Answer 20

Tadalafil

Question 21

A higher IC50 number indicates more…

Answer 21

Selectivity

Question 22

tMax

Answer 22

How long it takes for an oral inhibitor to reach peak concentration in the blood

Question 23

T 1/2

Answer 23

How long it takes for half the concentration to be cleared from the blood

Question 24

Which PDE5 inhibitor allows a patient to achieve an erection the fastest?

Answer 24

Vardenafil

Question 25

Do PDE5 inhibitors cause erections?

Answer 25

No. Smooth muscle relaxation does - PDE5 inhibitors allow it be maintained.

Question 26

Are PDE5 inhibitors vasoconstrictors or vasodilators?

Answer 26

Vasodilators - allows SM to relax

Question 27

Priapism

Answer 27

Rare condition causing persistent and often painful erections

Question 28

How is priapism treated?

Answer 28

Injection of phenylephrine (alpha-1) or surgical drainage

Question 29

Activation of alpha-1 receptors lead to…

Answer 29

smooth muscle contraction

Question 30

Can everyone take and/or respond to an oral PDE5 inhibitors?

Answer 30

No

Question 31

A different pathway (other than NO and cGMP) to stimulate erection. More stable synthetic form of prostaglandin E1.

Answer 31

Alprostadil

Question 32

How is alprostadil administered?

Answer 32

• Transurethral pellet
• Intracavernous injection (can cause scarring of tunica albuginea)

Question 33

Alprostadil stimulates _________.

Answer 33

• A decline in cytosolic Ca
• Adenylyl cyclase