QuestionSBA
QuestionChoice
This is a competitive antagonist which blocks the receptor site for catecholamines. This is often used to control the heart rhythm and also has a mortality benefit when used after a heart attack.
10005093
c
Propranolol at beta-adrenoceptors
QuestionChoice
This is an allosteric antagonist. This binds reversibly at a distant site from the agonist and causes a conformational change to the receptor. This prevents an agonist from binding to its active site and causing an effect.
10005091
a
Beta-carbolines at GABA(A) receptor
QuestionChoice
This is a competitive antagonist. It blocks the muscarinic acetylcholine (ACh) receptor to prevent activation of the parasympathetic nervous system.
10005092
b
Atropine at muscarinic receptors
QuestionChoice
This is a competitive antagonist. It is a PDE5 inhibitor which inhibits the degradation of cGMP and allows for vasodilatation of the vessels to occur.
10005094
d
Sildenafil at phosphodiesterase-5 (PDE5)
QuestionChoice
This is a competitive antagonist at the benzodiazepine site of the GABA(A) receptor. It is utilised to reverse a benzodiazepine overdose.
10005095
e
Flumazenil acting at the GABA(A) receptor
Concept
Chapter
2693
4370
Allosteric inhibition
Topic
180
Biochemistry
13565
Which one of the following is an example of an allosteric antagonist?
a