lecture 24: alkaloids 2 nicotine

Question 1

nicotine

Answer 1

antiherbivore chemical

Question 2

parasympathomimetic stimulant

Answer 2

stimulates LSNS, acetylcholine is neurotransmitter, highly addictive

Question 3

nAChR subtypes that nicotine targets

Answer 3

a7, a4B2
both subtypes release dopamine

Question 4

nicotine binding to nAChRs

Answer 4

opening of ion channels, Ca2+ flow inwards > release of neurotransmitters, growth / angiogenic factors
activate PKC > promotes proliferation, angiogenesis

Question 5

nAChRs (nicotinic acetylcholine receptors)

Answer 5

nicotine acts as agonist at nAChRs
respond to Ach and nicotine

transmit outgoing signals
expression of receptors upregulated by chronic nicotine exposure

Question 6

desensitization of a4B2

Answer 6

nicotine causes long term densensitization of a4B2

causes deficiency of GABA activity, GABA has a tumor-suppressor function

Question 7

a7 vs a4B2

Answer 7

in smokers, biological functions of a7 increased, a4B2 impaired

a7 inhibit of cancer cells
a4B2 stimulates GABA (tumor suppressor)

Question 8

cocaine

Answer 8

blocks removal of dopamine from the synapse > dopamine keeps binding with dopamine receptors

Question 9

acetylcholine vs nicotine release

Answer 9

half life of acetylcholine release is shorter, rapidly cleared from extracellular space, receptor binding affinity for nicotine is higher