Case Study: Nitric Oxide & Control Of Blood Fow - Viagra And Angina Pectoris

Question 1

2 pharmacological strategies for activating the NO system to dilate blood vessels + increase blood flow

Answer 1

1) Increase levels of cGMP by increasing NO levels
2) Increase levels of cGMP by blocking its degradation

Question 2

What conditions was sildenafil (known commercially as Viagra) originally developed to treat?

Answer 2

High blood pressure
Angina pectoris

Question 3

Angina pectoris

Answer 3

Chest pain (usually during exercise) caused by narrowing of coronary artery. REstriction of the artery allows for sufficient blood flow at rest bu cannot cope with the heart’s pcygen demand during exercise. The pain arises from the oxygen-deprived heart muscle

Question 4

Arterial narrowing can lead to

Answer 4

Chest pain (angina pectoris)
Heart attack (myocardial infarction)
Strokes

Question 5

What is cGMP degraded by?

Answer 5

Phosphodiesterase

Question 6

Action of sildenafil (Viagra)

Answer 6

Increases levels of cGMP by inhibiting phosphodiesterase 5 and thus preventing degradation; protein kinase G is therefore activated, inducing smooth muscle relaxation to increase blood flow to the penis

Question 7

How did Sildenafil (Viagra) become an erectile dysfunction treatment?

Answer 7

It was found during clinical trials to be more effective at treating erectile dysfunction than it was at treating angina pectoris. At the time of its FDA approval (1998) it had the fastest initial growth sales of any prescription product.