BP 2 - Drug receptor interactions

Question 1

What are the common drug targets?

Answer 1

Receptors
Enzymes
Ion channels
Carrier molecules

Question 2

What are the targets of drug action and medical use of benzodiazepenine?

Answer 2

GABA receptor

Anti-anxiety

Question 3

What are the targets of drug action and medical use of penicillin?

Answer 3

Transpeptidase

Antibiotics

Question 4

What are the targets of drug action and medical use of probenecid?

Answer 4

Organic ion transporter

Pronlong penicillin action

Question 5

What is an agonist and antagonist receptors?

Answer 5

1. Activate receptor

2. Block action against agonist

Question 6

What is the function of enzymes at a drug target?

Answer 6

Inhibit/act as false substrate

Question 7

What is the function of carriers at a drug target?

Answer 7

Block/ modulate opening/closing

Question 8

What is the function of ion channels at a drug target?

Answer 8

Transported in place of endogenous substrate/ inhibit transport

Question 9

What type of drug is benzodiazepine?

Answer 9

Anti-anxiety

Question 10

How does benzodiazepine work on GABAA receptor?

Answer 10

Increase of charge when is goes through the channel, however BZ just working on the channel does nothing, but used with GABA it enhances its effect

Question 11

What does NSAIDs stand for?

Answer 11

Non-steroidal anti-inflammatory drugs

Question 12

Give 2 examples of NSAID.

Answer 12

Ibuprofen and aspirin

Question 13

What is the effect of NSAID as a drug?

Answer 13

Inhibits cyclooxygenase, therefore arachidonic acid doesn’t convert into prostaglandins, in turn no inflammation, pain or fever

Question 14

How does histamine act as an agonist?

Answer 14

Attaches to H1 receptor in smooth muscle and increasing local blood flow

Question 15

How does terfenadine act as an antagonist?

Answer 15

Attaches to H1 receptor in smooth muscle to decrease local blood flow

Question 16

What are receptor subtypes and how do they differ?

Answer 16

Similar structures but significant differences in their pharmacological responses

Subtypes show many diff cellular effects due to diff specificities what activates/ inhibits them and diff signal transduction mechanisms

Question 17

Name 4 receptor types that respond to drugs?

Answer 17

Ligand gated ion channels
G-protein coupled receptors
Enzyme linked receptors
Intracellular receptors

Question 18

What else are channel linked receptors called?

Answer 18

Ionotropic

Question 19

What else are channel G-protein receptors called?

Answer 19

Metabotrophic

Question 20

What types of ionotropic receptors are there?

Answer 20

Ligand gated
Voltage gated
ACh binding site

Question 21

How do ligand gated receptors work?

Answer 21

Channel linked and need an agonist to open

E.g. nicotinic ACh receptor
ACh causes skeletal muscle to contract by opening channels

Question 22

How do voltage gated receptors work?

Answer 22

Need change in electrical charge across the membrane to open/close

E.g. Na+ channels in N cell membranes
LA block these channels

Question 23

What molecules make up the ACh binding site?

Answer 23

2 alpha, beta, gamma and delta

Question 24

Nicotinic ACh receptor antagonists are used for what?

Answer 24

Muscle relaxants

Question 25

What are the G-coupled receptors of epinephrine and salbutamol?

Answer 25

1. α/β adrenoceptors | 2. ß2 adrenoceptors

Question 26

What are the 3 subunits of a G-coupled receptor? and which molecule produces its specificity?

Answer 26

1. α, β, ɣ | 2. α

Question 27

G protein stimulatory action?

Answer 27

Activates adenylyl cyclase and Ca2+ channels

Question 28

G protein inhibitory action?

Answer 28

Inhibits adenylyl cyclase and K+ channels

Question 29

G protein q action?

Answer 29

Activates phospholipase C

Question 30

List the Gs protein signal transduction mechanism

Answer 30

- Hormone or NT binds to receptor - Occupied receptor changes shape and interacts with Gs protein - G protein releases GDP and binds GTP - Alpha subunit of protein dissociates and activates adenylyl cyclase - Adenylyl cyclase catalyses formation of cAMP - When no hormone/ drug the receptor reverts to its resting state

Question 31

Once α1 activated by Gq what function occurs?

Answer 31

Activates PLC | Vasoconstriction

Question 32

Once α2 activated by Gi what function occurs?

Answer 32

Inhibits adenylyl cyclase | Auto-inhibition of NT release

Question 33

Once ß1 activated by Gs what function occurs?

Answer 33

Stimulates adenylyl cyclase | Accelerated heart rate

Question 34

Once ß2 activated by Gs what function occurs?

Answer 34

Stimulates adenylyl cyclase | Bronchodilation

Question 35

What stimulates all subunit receptors?

Answer 35

NA and adrenaline

Question 36

What is a ß1 receptor antagonist?

Answer 36

Atenolol

Question 37

What is a ß2 receptor agonist?

Answer 37

Salbutamol

Question 38

What is a kinase linked receptor?

Answer 38

- Large extracellular ligand binding domain connected to intracellular domain by single memb spanning helix

Question 39

What forms of kinase linked receptors are there?

Answer 39

o Receptor tyrosine kinase – i.e. Insulin o Serine/threonine kinase o Cytokine o Guanylyl cyclase-linked

Question 40

How does a kinase linked receptor work?

Answer 40

1. Ligand binding 2. Dimerization 3. Autophosphorylation

Question 41

Nuclear receptor examples.

Answer 41

o Estrogen receptor – estradiol | o Estrogen receptor – tamoxifen

Question 42

Describe the classes of nuclear receptors.

Answer 42

Class I - in cytoplasm, form homodimers, ligands are endocrine (steroids, hormones) Class II - present in nucleus, form heterodimers, ligands are lipids (FA)

Question 43

What is a ß1 receptor antagonist?

Answer 43

Atenolol

Question 44

What is a ß2 receptor agonist?

Answer 44

Salbutamol

Question 45

What is a kinase linked receptor?

Answer 45

- Large extracellular ligand binding domain connected to intracellular domain by single memb spanning helix

Question 46

What forms of kinase linked receptors are there?

Answer 46

o Receptor tyrosine kinase – i.e. Insulin o Serine/threonine kinase o Cytokine o Guanylyl cyclase-linked

Question 47

How does a kinase linked receptor work?

Answer 47

1. Ligand binding 2. Dimerization 3. Autophosphorylation

Question 48

Nuclear receptor examples.

Answer 48

o Estrogen receptor – estradiol | o Estrogen receptor – tamoxifen

Question 49

Describe the classes of nuclear receptors.

Answer 49

Class I - in cytoplasm, form homodimers, ligands are endocrine (steroids, hormones) Class II - present in nucleus, form heterodimers, ligands are lipids (FA)

Question 50

What occurs when nuclear receptors bind to hormone response elements?

Answer 50

Starts gene transcription changes (+ve/-ve)

Question 51

List the mechanism of Class I nuclear receptor signal transduction.

Answer 51

- Lipid-soluble drug diffuses across the cell memb - Drug binds to receptor – changing shape and now activated, moving to nucleus - Drug-receptor complex binds to chromatin, activating transcription of genes - mRNA is translated into proteins that result in a specific biologic response

Question 52

What is the function of some molecules having multiple receptors binding sites for drugs?

Answer 52

Binding at one site will alter binding at another site (positive or negative)

Question 53

What are 3 drug-receptor interactions?

Answer 53

Allosteric sites Orthosteric sites Effector regions

Question 54

What is are orthosteric and allosteric sites?

Answer 54

Orthosteric, which bind at the active site; and allosteric, which bind elsewhere on the protein surface, and allosterically change the conformation of the protein binding site.