Pharmacology Exam 1

Front 1

pharmacologic classification of receptors

Back 1

based on the ligand to which the receptor binds.

Front 2

biochemical/biophysics classification of receptors

Back 2

based on the cellular response caused by receptor

Front 3

molecular or structural classification of receptors

Back 3

based on primary amino acid sequence

Front 4

classification of receptors based on anatomic location

Back 4

biological response in different tissues may be mediated by distinct receptors binding to the same drug/ligand.

Front 5

classification of receptors based on cellular location

Back 5

transmembrane receptors, intracellular receptors, nuclear receptors

Front 6

macromolecules that activate or are part of a signaling pathway

Back 6

surface growth factors receptors, neurotransmitters, nuclear hormone receptors, non metabolic enzymes

Front 7

macromolecules not associated with signaling pathway

Back 7

metabolic enzymes, transporters, ion channels, structural proteins, nucleic acids

Front 8

properties of protein based receptors for drugs

Back 8

recognition, saturability, reversibility, stereoselectivity, agonist specificity, tissue specificity,

Front 9

recognition

Back 9

the receptor protein must exist in a conformational state that allows for recognition and binding of a compound. Can have multiple states of high and low affinity

Front 10

saturability

Back 10

receptors exist in finite numbers

Front 11

reversibility

Back 11

binding occurs mainly through non-covalent weak intermolecular forces (H-bonding, van der Waal, etc)

Front 12

`stereoselectivity

Back 12

receptors should recognize only one of the naturally occurring optical isomers (many drugs exist in one or more conformations due to chiral center - a receptor can only bind one conformation)

Front 13

agonist specificity

Back 13

structurally related drugs should bind well, while structurally dissimilar compounds should bind poorly.

Front 14

tissue specificity

Back 14

receptors/drug targets can be tissue specific or they can be ubiquitous, depending on type. Drug receptors that are also receptors for endogenous ligands usually show tissue specificity.

Front 15

What is the most abundant receptor class?

Back 15

GCPR

Front 16

structure of GPCR

Back 16

Extracellular or TM domain containing ligand binding region

7 alpha helical membrane spanning domains 7-TM receptor

Intracellular domain that binds and activates G-proteins

Front 17

Gs

Back 17

Activates calcium channels, activates adenyl cyclase,

Front 18

Gi

Back 18

activates potassium channels, inhibits adenyl cyclase

Front 19

Go

Back 19

inhibits calcium channels

Front 20

Gq

Back 20

activates phospholipase C

Front 21

G12/13

Back 21

cytoskeletal remodeling

Front 22

role of G beta gamma

Back 22

increases affinity of G alpha for GDP and decreases GTPase activity

enhances affinity of G alpha for appropriate surface GPCR

interacts/activates potassium, calcium ion channels in heart, brain, phospholipase A2, phospholipase Cbeta, adenyl cyclase (different isoform from G alpha)

stimulates cell proliferation

Front 23

activation of phospholipase C leads to

Back 23

lipid metabolism, formation of DAG second messenger

Front 24

adrenergic receptors

Back 24

GPCR for catecholamines

Front 25

catecholamine hormones

Back 25

facilitate immediate physical reactions associated with a preparation for violent muscular action

Front 26

Flow of Neurotransmitters From CNS to Tissue in Autonomic Nervous System

Back 26

preganglionic neuron (in brain or spinal cord, myelinated) secretes acetylcholine to postganglionic neuron which has a nicotinic receptor. Postganglionic neuron (unmyelinated) secretes norepinephrine to a tissue which has an adrenergic receptor.

Front 27

nicotinic receptor

Back 27

an ionotropic receptor

Front 28

muscarinic receptor

Back 28

a GPCR

Front 29

alpha adreneric receptors

Back 29

located postsynaptically at neuroeffector junctions of many effector organs.

generally mediate excitation of effector organs.

Front 30

beta receptors

Back 30

located postsynaptically at sympathetic neuroeffector junctions or many organs.

generally mediate relaxation of effector organs.

**heart muscle is an exception to this rule**

Front 31

alpha receptors respond to...

Back 31

noradrenaline

Front 32

beta receptors respond to

Back 32

adrenaline

Front 33

beta 1 adrenergic receptors function to

Back 33

mediates heart muscle contraction

Front 34

beta 2 adrenergic receptors mediates..

Back 34

mediates smooth muscle contraction

Front 35

Beta 3 adrenergic receptors mediates..

Back 35

mediates fat breakdown (lipolysis)

Front 36

alpha 1 adrenergic receptors act by

Back 36

these adrenergic receptors have Gq bound to them which acitivates phospholipase C --> IP3 and DAG --> calcium increase

Front 37

alpha 2 adrenergic receptors act by

Back 37

these adrenergic receptors have Gi which inhibits adenyl cyclase,

Front 38

How does signaling through GPCR turn off?

Back 38

GTPase activity of Ga subunit converts GTP to GDP allowing rebinding to Gbg and inactivation of signaling.



Inactivation of GPCR following prolonged ligand binding: termed receptor desensitization

Front 39

tachyphylaxis

Back 39

receptor desensitization

Front 40

Homologous desensitization

Back 40

decreased response of one class of receptors to drug. likely point of action directly on receptor: negative feedback loop

Front 41

heterologous desensitization

Back 41

decreased responsiveness of multiple classes of receptor. likely point of action at a shared effector of all receptors in class

Front 42

mechanism of homologous desensitization

Back 42

activation of adenyl cyclase leads to PKA which phosphorylates the intracellular segment of the GPCR. beta adrenergic receptor kinase also phosphorylate the receptor. Beta arrestin binds to the phosphorylated segment and prevents the G protein from rebinding. This leads to homologous desensitization.

Front 43

receptor down regulation is a frequent mechanism of which types of receptors?

Back 43

main mechanism of tyrosine kinases.