Drug-Receptor Interactions Flashcards Preview

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Flashcards in Drug-Receptor Interactions Deck (18):
1

Receptor

a protein that is able to interact with molecules, whereby changing a cell's physiology

2

Ligand-gated receptors

Location: membrane

Time frame: milliseconds

Examples: nicotinic, acetylcholine

3

G-protein receptor

Location: membrane

Time frame: seconds

Examples: muscarinic, acetylcholine

4

Receptor kinase receptors

Location: membrane

Time frame: hours

Example: insulin

5

Nuclear receptors

Location: nucleus

Time frame: hours

Example: steroid

6

The ability of a cell to respond to a molecule is dependent upon _____?

whether the cell expresses the receptor that the molecule targets

7

Three characteristics of receptors

  1. they have finite lifespans
  2.  they undergo processes of synthesis and degradation
  3.  # can be affected by diseases and degree of stimulation (by exogenous or endogenous substances)

8

What roles do lysosomes play in receptor modification?

they are acidic organelle responsible for protein degradation in the endocytic and secretory pathways

9

How do proteosomes degrade proteins in a "discriminate fashion?"

they require a signal (e.g. ubiquitination) and typically target cytosolic or nuclear proteins

10

What is the Ubiquitous Protein System?

seeks and destroys damaged and excessive proteins by marking targets with ubiquitin/enzyme complex acting as a death signal to proteosomes

11

Receptor desensitization

a decline in the response to repeated or sustained application of an agonist due to changes at the level of the receptor; uncoupling b/t receptor activation and downstream effect (signaling efficiency has changed)

12

Receptor downregulation

receptors on surface are endocytosed or degraded due to repeated stimulation by an agonist; important for tolerance (e.g. opioid tolerance)

13

Tolerance

cellular response to repeated stimulation of a receptor is reduced; contributed to by both receptor downregulation and desensitization; is reversible

14

Tachyphylaxis

very acute, sudden decrease in response to receptor stimulation

15

Receptor upregulation

Increased # of receptors -- can be due to enhanced synthesis or decreased degradation/internalization

16

Receptor hypersensitivity

less stimulus is needed to produce an effect -- can be due to greater signaling molecules (increased signaling efficiency)

17

Agonist

Molecules that activate receptors; can be partial or full

18

What is the mechanism of action for partial agonists?

they compete for the same receptor and decrease a full agonist's activity