Bronchodilator: Muscarinic Antagonist Flashcards
How many types of cholinergic receptors are there?
1 - 5
2 - 4
3 - 3
4 - 2
4 - 2
- muscarinic and nicotinic
In the sympathetic nervous system, which neurotransmitter is released at the preganglionic neuron at the pre-synapse?
1 - acetylcholine
2 - noradrenaline
3 - dopamine
4 - serotonin
1 - acetylcholine
Acetylcholine is released at the preganglionic neuron. Which receptor does acetylcholine bind with at the post synapse of a neuron?
1 - nicotinic receptors
2 - adrenergic receptors
3 - muscarinic receptors
4 - GABA receptors
1 - nicotinic receptors
In the parasympathetic nervous system, which neurotransmitter is released at the postganglionic neuron where it stimulates its target tissue/cells?
1 - acetylcholine
2 - noradrenaline
3 - dopamine
4 - adrenaline
1 - acetylcholine
Acetylcholine is released at the postganglionic neuron where it comes into contact with target tissue/cells Which receptor does acetylcholine bind with at the post synapse of a neuron?
1 - nicotinic receptors
2 - adrenergic receptors
3 - muscarinic receptors
4 - GABA receptors
3 - muscarinic receptors
There are 5 types of muscarinic receptors M1-M5. M1, M3 and M5 all bind with the same GPCR, which one is this?
1 - Gaq
2 - Gai
3 - Gas
1 - Gaq
- M1 also has a little Gai and Gas
There are 5 types of muscarinic receptors M1-M5. M2 and M4 all bind with the same GPCR, which one is this?
1 - Gaq
2 - Gai
3 - Gas
2 - Gai
Gaq GPCR are present on alpha 1 receptors and become active when binding with adrenaline and/or noradrenaline. Organise the following intracellular pathway that occurs when these receptors become active?
1 - IP3 binds with the endoplasmic reticulum and opens Ca2+ channels, leading to increased intracellular Ca2+ and depolarisation
2 - pKC can then phosphorylate target proteins and induce cellular activity
3 - phospholipase C (PLC) becomes activated located in the cell membrane
4 - DAG binds protein kinase C (pKC) which becomes active due to increased Ca2+
5 - PLC cleaves hospholipid called phosphatidylinositol 4,5-bisphosphate (PIP2) forming inositol trisphosphate (IP3), which is soluble and diffuses freely in the cytoplasm, and the other part is diacylglycerol (DAG), bound to the cell membrane
3 - phospholipase C (PLC) becomes activated located in the cell membrane
5 - PLC cleaves hospholipid called phosphatidylinositol 4,5-bisphosphate (PIP2) forming inositol trisphosphate (IP3), which is soluble and diffuses freely in the cytoplasm, and the other part is diacylglycerol (DAG), bound to the cell membrane
1 - IP3 binds with the endoplasmic reticulum and opens Ca2+ channels, leading to increased intracellular Ca2+ and depolarisation
4 - DAG binds protein kinase C (pKC) which becomes active due to increased Ca2+
2 - pKC can then phosphorylate target proteins and induce cellular activity
Muscarinic receptors M2 and M4 have Gai GPCR present. What is the function of the Gai GPCRs?
1 - accentuates the activity of adenylyl cyclase
2 - inhibits adenylyl cyclase
3 - inhibits phospholipase C
4 - inhibits phospho kinase C
2 - inhibits adenylyl cyclase
- essentially inhibits the intracellular pathway of Gas
What is the main purpose of the muscarinic M3 receptors present on smooth muscle in the lungs?
1 - vasodilates smooth muscles
2 - increased permeability of epithelial cells
3 - reduced mucous secretion
4 - induces smooth muscle contraction
4 - induces smooth muscle contraction
- part of parasympathetic nervous system, so involved in rest
Which of the following is the short acting muscarinic antagonist (SAMA) drug do we need to know about?
1 - Formoterol
2 - Ipratropium bromide
3 - Salbutamol
4 - Serevent
2 - ipratropium bromide
Which 2 of the following is the long acting muscarinic antagonist (LAMA) drug do we need to know about?
1 - Formoterol
2 - Ipratropium bromide
3 - Tiotropium
4 - Aclidinium bromide
3 - Tiotropium
4 - Aclidinium bromide
What is the mechanism of action for SAMA and LAMA medications?
1 - inhibit Gas GPCR
2 - inhibit Gaq GPCR
3 - agonist of Gas GPCR
4 - agonist of Gaq GPCR
2 - inhibit Gaq GPCR
- compete with ACh at the post synapse
- essentially have anti-parasympathetic effects
Ipratropium bromide is the SAMA, and Tiotropium and Aclidinium bromide are the LAMAs. Which muscarinic receptor do these drugs target, and which GPCR is present there in lung tissue?
1 - M1 with Gas
2 - M1 with Gaq
3 - M3 with Gaq
4 - M3 with Gas
3 - M3 with Gaq
- essentially reduce/stop bronchoconstriction
- BUT not as effective as Salbutamol (SABA)
The SAMA, Ipratropium bromide typically has two key indications, which are?
1 - chronic preventer in COPD
2 - acute reliever in COPD for acute breathlessness or COPD exacerbation
3 - chronic asthma alongside LABA and inhaled corticosteroid
4 - acute severe asthma alongside salbutamol (SABA)
2 - acute reliever in COPD for acute breathlessness or COPD exacerbation
4 - acute severe asthma alongside salbutamol (SABA)
- generally given via a nebuliser