Receptors

Question 1

Receptors and ligands

Answer 1

ligand is a chemical, substance that binds to receptor

Receptor Protein intra or exta cellular component ligand/drug bind to start chain of bio actions by drugs effect

Question 2

Receptor concepts

Answer 2

Determing quantiitvative info, drug dose, effect.
Drug respone=#of drug receptor complexes
Selective
Bilion of yr old
Drug 100y
Medicate action of drug agonist or antagonist

Question 3

Types of drug receptors

Answer 3

Proteins- Reg proteins, enymes, transport, structall cell components
DNA, RNA
Ribosomes, synthetic?

Question 4

Enantiomers and receptor binding

Answer 4

?

Question 5

Law of mass action and drug receptor binding

Answer 5

Theory-Kon Koff rates controls
Assumes- all receptors are equally accessible to drug
Partial binding not accounted
Drug is not altered by bind
Binding reversilbe

Drug + Receptor__Drug-Receptor contration. More subtrates dissoactes to product. vice versa

Question 6

Potency vs efficacy

Answer 6

Efficacy- maximal response a drug produces. More important when selecting drug.
Potent- amt of drug (EC50) req. to produce 50% of max effect, determine Pt dose.

More potent= less drug concentration in o/t reach efficacy

Question 7

Quantal dose response curve

Answer 7

inc. fraction of a pop. that shaw a specif respon at progressing inc does.
Sigmoid shape
Digital respons-yes, no, “HA gone yes”
ED, LD

Question 8

ED50, TD50 LD50 , Kd

Answer 8

median effective dose- “Yes pain gone”
Toxic does
Lethal does
Grade dose, concentration of dose that cause 50% of max effect or toxicity.
Quantal- concentration or dose that cause effect in 50% population

Kd- concentration of drug that bind to 50% of avail receptors

Question 9

Receptor effector coupling

Answer 9

transduction of drug+recptor= biological response

cascade of events

Question 10

Spare receptors concept

Answer 10

Max effect produced but not all receptors filled Kd>ED50

If Ed50

Question 11

Receptor conformation , Ri and Ra

Answer 11

Drugs that shift to Ractive to R inactive receptor pool, Low intrsicic efficacy

Question 12

Inverse agonist

Answer 12

Drug+receptor= biological response by altering cell state, tips toward inactive, decrease effect

Bind to Ri, drives pool toward Ri
Benzodiaepines at GABBA receptor-inc. flow of Cl to shut down neuron

Question 13

Types of antagonists

Answer 13

Competitive response by blocking, but can get kicked off
Epinephrine kicks off propranolol aftr exercises

Noncompetivie- no matter how much agonist, recepter remained blocked
Many sites to block

Keep Ra and Ri proportion in balance

Question 14

Chemical vs physicological antagonism vs pharmoclolgical

Answer 14

chemical- blocks other drug, use drug to kill other drug binding

Phys- drug that encounters another drug, bind to diff site for opposite effect. hcortisone inc gluclose levels, insulin to stop

Rx-drug that binds with no acitvation

Question 15

Receptor desensitization

Receptor down and up regulation

Answer 15

no response on some or over time
Receptors less receptors
Changes in concentration endogenous receptor ligand
Change in components of response distal to receptor
Alteration in drug concentration wen it reaches receptor

Question 16

Therapeutic index

Answer 16

measure of drugs toxicity
TD(LD):ED ratio
Death ultimate toxic
quantal dose based- population animals only

Question 17

Therapeutic range/windo

Answer 17

range of concentration of drug in the blood that will have max effect
Anything below {} will not work
Anything above {} will be toxin
Small range helpful but kill many
Large ranges very available bbut side effects

Question 18

Lipid soluble, intracellular

Answer 18

drug diffuses thru membrane to bind to intracelluar receptor- 
STEROID- allow transciption to initate
Take hrs for effect
2d duration
Highly lipid soluble drugs

Question 19

Activate IC enzyme domain

Ligand regulatd transmembrane

Answer 19

28% of drugs
w/in membrane.
outer layer- provides receptor fx
IC layer- l/t regulate IC enzyme A to B, product
Insulin-binds l/t IC enzyme activation
Sugar-so much in system, receptors desensitzed when it binds, overworked. insulin resistance

Question 20

Activate IC tyrosine kinase (cytokine receptor)

Answer 20

bind IC tyrosine kinase enzymes (JAKs-STAT receptors
transcription regulators
Growth hormone

Question 21

Ligand Ion gated channel

Answer 21

5%
protein opens or closes by drug-receptor binding
ACh, GABA

Question 22

G Protein coupled receptor, serpentine

Answer 22

MOST drugs 45%**
stimulates G-protein, which produces 2nd messenger
INC. IC calcium or cAMP
1- extracelluar receptor
2- G-protein on inner face
3- activates enzyme or open/close ion gate

Question 23

Agonist

Answer 23

Drug+receptor= biological response

Question 24

Partial agonist

Answer 24

Drug+receptor= but biological response not 100% even with high dose
Buprenorphine- partial to opiod, safe less respirtory response than morphine

Question 25

Antagonsit

Answer 25

Drug+receptor= blocks biological response by blocking agonist or natural agents

Question 26

Naxolone

Answer 26

removes overdose effects- on the market

if opiods are bound to receptor it can revers biologcial effect of naxolone

Question 27

tachyphlaxis

Answer 27

rapid dec in drug response few sec.

Everybody diff, if someone not respoding offer dose or new drug. Don’t blame Pt.