Concepts & terms

Question 1

activates the receptor as a direct result of binding to it

Answer 1

agonist

Question 2

produces a lower response at full receptor occupancy; concentration curve resembles that of the full agonist with some antagonist bound to the receptor sites

Answer 2

partial agonist

Question 3

binds to the receptor but doesn’t activate generation of a signal; primary action is to interfere with the action of the agonist

Answer 3

antagonist

Question 4

competes with the agonist for the receptor site

Answer 4

competitive antagonist

Question 5

duration of action of irreversible antagonist

Answer 5

largely determined by the rate of turnover of the receptors and not its rate of elimination

Question 6

the concentration of drug that produces 50% of max effect

Answer 6

EC50

Question 7

the transduction process that links drug occupancy of receptors and pharm response

Answer 7

coupling

Question 8

helps elicit a maximal biological response at a concentration of agonist that does not result in occupancy of the full complement of available receptors

Answer 8

spare receptors

Question 9

can cross the plasma membrane and act on an intracellular receptor

Answer 9

corticosteroids
mineralocorticoids
sex steroids
vitamin D
thyroid hormone

Question 10

endogenous ligands that regulate the flow of ions through the plasma membrane

Answer 10

acetylcholine
serotonin
GABA
glutamate

Question 11

G protein-coupled receptor NTs/ligands

Answer 11

adrenergic amines
serotonin
muscarinic ACh
peptide hormones
odorants

Question 12

degrades cAMP and IP3, respectively

Answer 12

caffeine (cAMP)
lithium ion (IP3)

Question 13

the dose of drug required to produce 50% of maximal effect of the drug; refers to the potency

Answer 13

ED50 = median effective dose

Question 14

dose required to produce a toxic effect in 50% of animals

Answer 14

TD50 = median toxic dose

Question 15

toxic dose required to produce death in 50% of animals

Answer 15

LD50 = lethal toxic dose

Question 16

the ratio of the TD50 to the LD50

Answer 16

therapeutic index

Question 17

what the body does to a drug:
absorption
distribution
metabolism
excretion

Answer 17

pharmacokinetics

Question 18

what the drug does to the body:
side effects
toxicity
withdrawal reactions

Answer 18

pharmacodynamics

Question 19

mimic actions of epinephrine or NE

Answer 19

sympathomimetics

Question 20

directly interact with and activate adrenoreceptors

Answer 20

direct agonists

Question 21

actions depend on the abilities to enhance the actions of endogenous catecholamines

Answer 21

indirect agonists

Question 22

intracellular signaling pathway that promotes release of sequestered Ca2+ increasing intracellular calcium and activating calcium-dependent kinases

Answer 22

IP3

Question 23

activates protein kinase C

Answer 23

DAG

Question 24

enzyme that increases cAMP
beta receptors and D1 receptors activate this enzyme
alpha 2 and D2 receptors inhibit it

Answer 24

adenylyl cyclase

Question 25

primary location of beta 1 receptors

Answer 25

heart

activation increases contractility and direct activation of the SA node

Question 26

mediate urinary continence

Answer 26

alpha receptors in bladder base, urethral sphincter and prostate
Note: alpha1 receptor activation causes constriction

Question 27

receptor that plays a role in normal ejaculation

Answer 27

alpha

Question 28

agonist at both alpha and beta receptors

• potent vasoconstrictor & cardiac stimulant
• increases HR and contractility

Answer 28

epinephrine

Question 29

agonist of both alpha and beta1 receptors

• increases peripheral vascular resistance in both systolic and diastolic bp
• compensatory baroreflex of heart overcomes the chronotropic effects, but positive inotropic effects are maintained

Answer 29

norepinephrine

Question 30

immediate precursor to NE

Answer 30

dopamine

Question 31

action of indirect-acting sympathomimetics

Answer 31

they are “amphetamine-like” because they displaced stores catecholamine NT and interfere with NET