Cell Signaling

Question 1

Paracrine Signaling

Answer 1

a form of signaling where a cell produces a signal to induce changes in nearby cells

Question 2

properties of Paracrine agents

Answer 2

rapidly degraded, only effects local tissue, does not enter the blood stream

Question 3

Autocrine signaling

Answer 3

a form of signaling where a cell secretes a hormone or chemical messenger that binds to the same cell to induce changes in the same cell

Question 4

properties of Autocrine agents

Answer 4

action on the same cell that secreted them

Question 5

responses of Autocrine agents are mediated by receptors in the

Answer 5

membrane, cytoplasm, and nucleus

Question 6

Eicosanoids

Answer 6

locally acting fatty acid hormones, made from arachidonic acid, located in the plasma membrane

Question 7

Eicosanoids examples

Answer 7

Prostaglandin
Thromboxane
Leukotrienes

Question 8

Phospholipase A2

Answer 8

converts phospholipid to Arachidonic acid
inhibited by Glucocorticoids

Question 9

Cyclooxygenase

Answer 9

converts arachidonic acid to Endoperoxides
inhibited by Aspirin and NSAIDs

Question 10

Subtypes of Cyclooxygenase

Answer 10

COX 1 - platelet aggregation pathway, protects stomach
COX 2 - pain and inflammation pathway
COX 3 - fever link? (recently discovered)

Question 11

Prostacyclin Synthase (PGI2, prostaglandin I2)

Answer 11

vasodilator, bronchodilator, decreased platelet aggregation

Question 12

Thromboxane Synthetase (TxA2)

Answer 12

vasoconstrictor, bronchoconstrictor, increased platelet aggregation

Question 13

Leukotrienes

Answer 13

involved in asthmatic and allergic reactions, stimulated T cells, interleukin, interferon production, bronchoconstriction, increased vascular permeability

Question 14

Action of NSAIDs and Aspirin

Answer 14

inhibits Cyclooxygenase

Question 15

Aspirins

Answer 15

anticlotting pathways, can lead to ulcers

Question 16

Ibuprofens

Answer 16

inhibit inflammatory reaction in pathway (PGI2) inhibits COX 1 & 2

Question 17

Naproxen (Aleve)

Answer 17

similar action to ibuprofen

Question 18

Indomethacin

Answer 18

removed pain and swelling (arthritis)

Question 19

Cox 2 inhibitors

Answer 19

inhibits pain/inflammation pathway without altering clotting,

Question 20

High doses of ibuprofen for 18 months doubles heart attack chance

Answer 20

True

Question 21

Acetaminophens

Answer 21

analgesic, antipyretic, may inhibit COX 3 pathways

Question 22

New anti-asthmatic/anti-allergy medications

Answer 22

block leukotriene pathways

Question 23

Signal Transduction

Answer 23

Signal = receptor activation
Transduction = stimulus transformed into a response

Question 24

Lipid Soluble messages

Answer 24

steroid hormones
intercellular receptors
regulate gene transcription

Question 25

Lipid Insoluble messages

Answer 25

utilize plasma membrane receptors several models of action

Question 26

First Messenger Systems

Answer 26

1. Receptor Coupled with Ion Channel 2. Receptor Coupled with Protein Kinase

Question 27

Receptor Coupled with Ion Channel

Answer 27

messenger binds to receptor receptor activated gated ion channel

Question 28

Receptor Coupled with Protein Kinase

Answer 28

messenger binds to receptor receptor binds to Tyrosine Kinase which Phosphorylates Protein mediates cell response in growth and development

Question 29

Second Messenger Systems

Answer 29

activate G proteins cAMP, IP3, DAG, Ca++ 1st messenger - receptor - G Protein - Effector Protein - 2nd Messenger, G Protein couples receptor and effector

Question 30

Cyclic AMP (cAMP)

Answer 30

second messenger, Adenyl Cyclase is the Effector, activates protein kinases, phosphorylates proteins (inhibit or stimulate)

Question 31

phosphodiesterase

Answer 31

degrades cAMP into 5" AMP, blocking this with caffeine augments cAMP and Guanylyl Cyclase Analog (cGMP) effects

Question 32

Guanylyl Cyclase Analog (cGMP)

Answer 32

responsible for vision

Question 33

IP3, DAG

Answer 33

second messengers, Phospholipase C is the Effector, PIP2 converted into IP3+ DAG

Question 34

DAG

Answer 34

activates protein kinases, phosphorylating proteins, mediates cell responses

Question 35

IP3

Answer 35

makes ER membranes leaky to Ca++, increases cytosol Ca++, mediates cell responses

Question 36

Intracellular Ca++ is increased by

Answer 36

G Proteins activating membrane Ca++ gates, IP3 mediating the release of Ca++ from the ER, active transport of Ca++ out is blocked by a 2nd messenger, opening of voltage gated channels

Question 37

Calcium MoA

Answer 37

1. Ca++ bind to Calmodulin (changes protein shape, activation or inhibition) 2. Ca++ binding to enzymes 3. Ca++ binding to proteins (alters conformation and reactions) 4. Ca++ mediates neurotransmitter release

Question 38

caffeine

Answer 38

worlds most widely consumed psychoactive drug, 90% of adults each day use caffiene

Question 39

caffeine Methylxanthine

Answer 39

coffee, tea

Question 40

caffeine Theobromine and Theophylline

Answer 40

chocolate and tea Theobromine family = vasodilators for the brain

Question 41

caffeine MoA

Answer 41

blocks Adenosine receptors, inhibits Acetylcholinesterase, Blocks phosphodiesterase (increases cAMP), stimulates neurotransmitters(ACh, E, NE, DOPA, Sero)

Question 42

Adenosine

Answer 42

neuromodulating agent, downregulates CNS activity, can accumulate and trigger sleep