L61- Basic Pharmacology

Question 1

What is an allosteric modulator?

Answer 1

a substance which indirectly influences the effect of an agonist or inverse agonist at a target protein they can activate a recptor

Question 2

what do allosteric modulators do?

Answer 2

bind to site distinct from the orthosteric agonist binding site

Question 3

what are the 2 types of allosteric modulators and what do they do?

Answer 3

• positive allosteric modulators induces an amplification of the agnostic effect
• negative allosteric modulators inactive in the absence of the orthosteric ligand

Question 4

how do allosteric modulators affect receptor function?

Answer 4

they can affect:

• orthosteric-ligand affinity
• orthosteric ligand efficacy
• direct allosteric agonism

Question 5

what is a homodimer?

Answer 5

when 2 identical receptors interact?

Question 6

what is receptor desensitisation GPCR?

Answer 6

when there is a decrease in responsiveness due to repeated expose to agonists.

Question 7

what is receptor sequestration GPCR?

Answer 7

when receptors disappear from the CSM after receptor occupancy mediated by internalisation of GPCR via endocytosis

Question 8

what is down regulation of GPCR?

Answer 8

receptor occupancy for minutes to hours results in a net loss of total receptors from cells

Question 9

What is tolerance?

Answer 9

its the decreased or failed response to the usual therapeutic dose of a drug

Question 10

what are the 2 types of tolerance?

Answer 10

• congenital: existing from birth
• Acquired : resistance due to usual dose of a drug repeatedly administered and ,ore of drug is needed to produce same effect e.g. cocaine

Question 11

what is tachyphylaxis

Answer 11

type of acute form of acquired tolerance occurring in few minutes possibly due to saturation cell receptors with the drug. Increasing the dose can’t produce same effect