Flashcards in 9.12 Pharmacology 3 Deck (30)
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1
components on or within the cell to which a substance binds
receptors
2
How do surface receptors act as ion channels?
directly alter membrane permeability
3
How do surface receptors act to directly influence cell function?
enzymatically
4
Purpose of surface receptors linking to regulatory proteins
regulatory proteins control other chemical or enzymatic processes
5
affinity
- attraction of a drug to a receptor
- determines how it will bind and react
6
efficacy
How well a drug binds and reacts to with a receptor
7
How do drugs affect change through binding?
The drug finds and occupies a receptor, then somehow interacts with it to change cell function
8
agonist
drug that can bind to a receptor and initiate a change
9
What do agonist drugs have?
- affinity
- efficacy
10
Antagonists ONLY have
affinity
11
How do antagonists work?
- binds to receptor
- does not initiate a change
- blocks the effect of another chemical and prevents action
12
antagonists aka
blockers
13
beta blockers are used to treat
HTN
14
competitive antagonist
both the agonist and the antagonist have an equal opportunity to occupy the receptor
15
For a competitive antagonist vs. an agonist, which will win out for receptor spots?
whichever has the highest concentration
16
What happens if a competitive antagonist "wins"?
inhibition
17
Competitive antagonists generally require a (higher/lower) concentration. Why?
- higher concentration
- weak bones
18
noncompetitive antagonist
- irreversible
- strong bonds formed
- cannot be displaced by the agonist
19
How long do noncompetitive antagonist drugs last?
- entire lifespan of the cell
- usually several days
20
partial agonist
- don't get a full response
21
Partial agonists have:
- affinity
- don't have full efficacy
22
Clinical advantage to partial agonist drugs?
fewer side effects
(i.e. cardiovascular and antipsychotics)
23
mixed agonist-antagonist
can stimulate certain receptors while blocking others
24
Example of mixed agonist-antagonist
selective estrogen receptor modulator (ex. tamoxifen used in breast cancer)
25
How does tamoxifen work as a mixed agonist-antagonist?
- stimulates estrogen receptors to prevent osteoporosis
- blocks effects on breast tissue to prevent cancer
26
inverse agonist
- binds to same receptor as an agonist
- has opposite effect
27
Uses for inverse agonists?
- could slow down overstimlulated receptors
- research in antipsychotics and beta blockers
28
desensitization
- cell becomes less responsive
- can decrease active receptors
29
down-regulation
slower version of desensitization
30
