Lectures 4-6

Question 1

What is the function of angiotensin II in the body, what is it made from, and what enzyme catalyses the conversion of the precursor into angiotensin II?

Answer 1

Angiotensin I is converted into Angiotensin II by the Angiotensin converting enzyme (ACE)

Question 2

What is used prevent the formation of angiotensin II, what drug is used for this and why?

Answer 2

Angiotensin II formation is prevented by an ACE inhibitor, this can be achieved by the drug Captopril.

This is used to treat hypertension.

Question 3

How does viagra work and what is it used to treat?

Answer 3

Cyclic GMP causes smooth muscle relaxation causing an erection.

Viagra prevents the conversion of cyclic GMP into non cyclic GMP preventing erectile dysfunction.

Question 4

How does digitoxin work and what is it used to treat?

Answer 4

Digitoxin inhibits the potassium ion pump by preventing the conversion of ATP to ADP.

This prevents Potassium ions being pumped into the cell.

This increases the force of cardiac contraction. and is why digitoxin is used to treat congestive heart failure.

Question 5

What is the intracellular and extracellular concentration of calcium ions?

Answer 5

Intracellular - 100 nM.

extracellular 1.5 mM.

Question 6

What is an example of a drug that blocks calcium ion channels and what is it used to treat?

Answer 6

Nifedipine is used to treat hypertension.

Question 7

What are 2 examples of drugs that block sodium ion channels?

Answer 7

Tetrodotoxin

Lignocaine - used as an anesthetic.

Question 8

What does ED50 mean?

Answer 8

ED - effective dose

ED50 - The concentration of drug produces a therapeutic effect in 50% of the population.

Question 9

What does TD50 and LD50 mean

Answer 9

TD - toxic dose

TD50 - The concentration of drug that produces a toxic effect in 50% of the population.

LD - Lethal dose

LD - The concentration of drug that results in death in 50% of the population.