11. Para/ Sympathetic drugs

Question 1

Answer 1

Question 2

characterisation of muscarinic receptors

Answer 2

• Activated by muscarine not nicotine
• All act via metabotropic, not ionotropic, events
• Family of at least 3 members (mAChR)

–M1 brain “neural”

–M2 heart “cardiac”

–M3 smooth muscle/exocrine “glandular”: mobilise IC calcium

•Utilise different 2nd messengers

–intracellular Ca2+ release & protein phosphorylation

•Act on different effector/target proteins

–e.g. contractile proteins, ion channels

Question 3

molecular mechanism of M2 to inhibit camp

Answer 3

Question 4

molecular mechanism of M2 to activate receptors: potassium direct

Answer 4

Question 5

what is the treatment for glaucoma

Answer 5

•Glaucoma

–tunnel vision & blindness

–build up of intraocular pressure increase compress optic nerve

–excess aqueous humour

•Treat with M3 agonist, Pilocarpine to promote miosis. Why?

1. Constriction of circular muscle
2. opens up drainage channel
3. ­ increase aqueous humour drainage
4. decrease intraocular pressure.

Question 6

Indirectly acting parasympathomimetics:

Answer 6

Block termination of neurotransmission of SNS

eg. anti-chE elevate Ach