Uses of agents that modify adrenoreceptors and chlinoreceptors

Question 1

What type of receptor is muscarinic?

Answer 1

G protein coupled receptor

Question 2

what type of receptor is nicotinic?

Answer 2

Ligand-gated ion channel receptor

Question 3

what are the two receptor types activated by acetylcholine?

Answer 3

muscarinic

nicotinic

Question 4

what are the clinical uses of cholinoceptor agonists, muscarinic?

Answer 4

Pilocarpine (mAchR agonist) used to treat glaucoma and dry mouth

Bethanecol (mAchR) used in bladder/gastric emptying

Question 5

what are the clinical uses of cholinoceptor agonists, nicotinic?

Answer 5

more limited in use (as nicotinic receptors are in all autonomic ganglia)

used in surgery - depolarising paralysis, stopping contractions.

Question 6

what is the role of the cholinesterase enzyme?

Answer 6

it hydrolyses Ach into choline and Acetic acid in the nerve junction

Question 7

what are the clinical uses of cholinesterase inhibitors?

Answer 7

In conditions of low levels of Ach.
Dementia
Neuromuscular diseases: myasthesia gravis

Question 8

what do cholinesterase inhibitors do?

Answer 8

they inhibit the breakdown of Ach.

Increasing Ach in the NMJ helps overcome deficit in early stages of diseases (specifc)

Question 9

what are some of the clinical uses of muscarinic blockers?

Answer 9

hyoscine = premedication before anaesthesia to reduce secretions + prevents vagal slowing of the heart

Question 10

where are muscarinic receptors found?

Answer 10

secretory cells
SAN
Vascular smooth muscle

Question 11

what is the benefit of hyoscine compared to ipatropium?

Answer 11

hyoscine can penetrate the brain = better sedation

Question 12

what is anticholinesterase poisoning and how is it treated?

Answer 12

From insecticides containing parathion (long lasting cholinesterase inhibitor)
patients present with cholinergic overdrive
salivating, crying, urinary incontinence
treated with muscarinic blockers

Question 13

what are the clinical uses of nicotinic blockers?

Answer 13

muscle relaxants, can be used during surgery (direct nAchR blockers)

depolarising blockers (direct nAchR agonists)

Question 14

what type of receptors are adrenoreceptors?

Answer 14

G protein coupled receptor

Question 15

where are adrenoreceptor agonists clinically used for?

Answer 15

Eye drops
Asthma inhalers
cardiac stimulants = dopamine and adrenaline (b1 agonists)

Question 16

what is the mechanism of salbutamol?

Answer 16

Beta 2 agonist, widens airways

Question 17

what are the main uses of beta adrenoreceptor blockers?

beta 1 adrenoreceptor

Answer 17

heart failure = atenolol
slows heart rate reducing demand on myocytes
reduced arrythmia

kidneys = reduces renin release
angiotensin converted to angiotensin 2= vasoconstrictor

Question 18

what are the main uses of alpha adrenoreceptor blockers?

Answer 18

high blood pressure = Prazosin

adrenal gland tumour

Question 19

How can a beta 1 antagonist affect the heart?

Answer 19

it can lower heart rate

Question 20

How can a non selective beta blocker effect the eyes?

Answer 20

Timolol can stop ocular fluid production

Question 21

what is the mechanism of atropine?

Answer 21

muscarinic blocker = vagal induced slowing of heart rate