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Flashcards in Murphy Receptors Deck (13):
1

Drug Receptor Anatomy

Described as lock and key fitting for receptor activation

2

Location of target proteins for current drugs

Cell Membrane - 62%
Unknown - 15%
Exterior - 8%
Cytoplasm - 6%
Nucleus - 6%
Organelles - 4%

3

4 Superfamilies of Physiologic Receptors

Ion Channel Receptors
G-Coupled Protein Receptors (GPCR)
Enzyme Receptors
Nuclear Receptors

All are effected by agonists

4

Adrenergic Receptors

Denoting nerve cells in which epinephrine and norepinephrine act as neurotransmitters.

5

Subclass of Adrenergic Receptors

Drugs can be selective or non selective for all of these:

---------------------------------------------------a-1A
----------------------------------Alpha 1 ------a-1B
---------------------------------------------------a-1D
-Alpha Receptors -------
---------------------------------------------------a-2A
----------------------------------Alpha 2 -----a-2B
---------------------------------------------------a-2C
---------------------------------
---------------------------------------------------B-1
-Beta Receptors----------------------------B-2
---------------------------------------------------B-3

6

Specific Drugs

Drugs that only have 1 target (rare)

7

Selective Drugs

When at a given concentration a drug only has 1 target

8

Non-Selective Drugs

Drugs that have more than one target at a given concentration

9

Types of chemical bonding forces

Ionic
Hydrogen
Van Der Walls
(Covalent)

10

Kd

Dissociation constant which is determined by the affinity of a receptors to drugs based on ligand concentration. Kd can be described as the concentration of ligand at equilibrium that causes a percentage of receptors to be ligand bound. Kd = concentration of drug occupying 50% of receptors.

11

Fractional Occupancy

The fraction of receptors occupied at a particular ligand concentration. Fractional Concentration = LR / R (tot)

12

Effect of Kd on Potency

A low Kd will equate to a high drug affinity to receptors and therefore a high potency

A high Kd will equate to a low drug affinity to receptors and therefore a low potency

13

Explain why EC50 does not equal Kd most of the time

Non-Linear systems
Receptor activation equilibrium
Competition with endogenous activators
Impaired drug access to receptors