Lectures 16-20 Flashcards
What is hexamethonium?
A non-competitive antagonist for nAChR’s
Why is hexamethonium not used anymore?
It blocks effects of both ParaNS and SympNS, this doesn’t make much sense
What are parasympathomimetics?
muscarinic agonists, used to mimic the effects of the ParaNS
What maineffects do parasympathomimetics have?
Decrease heart rate
Increase sweating
Contraction of smooth muscle in the gut particularly
How might parasympathomimetics interact with blood vessels?
stimulate the release of endothelial derived relaxing factors (EDRF’s) - causing dilation
How would you treat muscarinic poisoning?
Atropine - muscarinic antagonist
What is Pilocarpine used for?
It is a localised muscarinic agonist, and is an eye drop for glaucoma treatment. It binds to muscarinic receptors on ciliary muscle, improving humour drainage, decreasing intraocular pressure
Where are the main sub-classes of specific muscarinic antagonists found?
M(1) - stomach, salivary glands
M(2) - cardiac
M(3) - smooth muscle
What is atropine?
A non-specific muscarinic antagonist
What are the different types of adrenoreceptors?
Alpha (2) - vasocantriction
Beta (3) - increase heart rate, smooth muscle relaxation
What are the specific functions of alpha adrenoreceptors?
1 - contract smooth muscle (vasoconstriction))
2 - pre-synaptic auto-inhibition (direct vasocontriction)
What are agonists of alpha adrenoreceptors used for?
Vasocontrictors with Local Anaesthetics or as Nasal decongestants
What are the uses of alpha adernoreceptor antagonists?
for hypertension and benign prostatic hyperplasia
What do the different beta adrenoreceptors do?
1 - increase heart rate
2 - relax cardiacsmooth muscle
3 - relax bladder smooth muscle (and induce lipolysis)
Name one use of beta adrenoreceptor agonists
asthma treatment
