Agonist and antagonist

Question 1

What is a full agonist?

Answer 1

Full agonist - the drug bind to the alpha-1 receptors 100%, it saurates and makes the same maximal vasconstruction.

Question 2

What is partial agonist?

Answer 2

Partial agonist- drug b binds to the alpha-1 receptors 100%, it saturates but it doesnt have the same maximal effects as full agonist.

Question 3

What is inverse agonist?

Answer 3

Inverse agonist- Drug c binds to the alpha-1 receptor 100% but the recpetor is inactive and the maximal effect is decreased below the basal activity of 12%.

Question 4

Give an example of the full agonist?

Answer 4

Drug e.g norepinephrine, phenylephrine and epinephrine bind to the receptor 100%, it is then saurated and it will all have the same maximal vasconstruction effect.

Question 5

Give example of the partial agonist?

Answer 5

Drug e.g bupreorphrine binds to the Mu receptor, it is saturated but it doesnt have the same maximal effect as full agonist
Bupreorphrine and morphine together- the bupreorphrine binds to the receptors blocking the morphine from binding the only way morphine can bind to the Mu receptor is if there is an increase in the concentration.

Question 6

Give example of the inverse agonist?

Answer 6

Drug-antihistamines binds to the H1H2 receptors, which inactive the receptor and the maximal effect will decrease.

Question 7

What does the antagonist do in the graph?

Answer 7

The antagonist acts as a neutral component.

Question 8

What is competitive antagonist?

Answer 8

1.Alpha blockers such as phentoamine block the norepinephrine from binding to the alpha receptors

2.However if there is an increase in norepinephrine concentration, then it can take the space and bind to the receptors instead
3.When that happen the potency will increase the EC50 and the potency will decrease (The Emax is left alone).

Question 9

What is non-competitive antagonist?

Answer 9

1.A alpha blocker such as Phenoxybenzamine binds to the allostic site (Near the active site of the receptor).
2.However when it is binded here it changes the shape of the receptor making it hard for the drug such as norepinephrine to bind
3.So norepinrphrine can no longer bind to the receptor even if there is an increase in the concentration it stil can not happen.
4.The EC50 is left alone but the Emax is increases.