Asthma Flashcards
What is asthma?
Chronic inflammatory disorder of the airways
Name some smooth muscle growth regulators
Mitogens
- platelet dervied growth factor
- endothelin
- cytokines
- histamine
Modulators
- heparin
- NO
- Prostaglandin E2
Ach and eNANC stimulate what?
GPCR (leading to elevation of intracellular free calcium)
M3 receptor is couples to GI, Gs or Gq?
Gq-PLC
M3 receptor stimulation causes what?
Contraction
M3-Gq-PLC-__-Ca2+-MLCK-___
IP3
Contraction
Muscarinic antagonists aren’t commonly used in mild/moderate asthma, true or false?
True
Neuronal Ach release is inhibited by what?
M2 receptor feedback
Parasympathetic nerve releases what?
ACh
Loss of M2 feedback could lead to what?
Enhanced airway contraction
What are the 3 mechanisms of hyperresponsiveness in asthma?
Increased smooth muscle contractility.
Increases excitory nerve activity.
Decreased bronchodilator activity.
What mechanism does adrenaline use to be a bronchodilator?
Acts on B-adrenoceptors on airway smooth muscle
Name two dilator neuropeptides
CGRP
VIP
What do CGRP and VIP both activate?
AC
What does neuronally derived NO act on?
Soluble guanylate cyclase
B2-Gas-AC-cAMP-PKA=?
Open K+ channels
Inactivates MLCK
Calcium sequesteration
What is isoprenaline?
Non-selective B agonist
What is salbutamol?
Short acting selective B2 agonist
What is formoterol?
Long acting B agonist
Which is most lipophilic out of salmeterol, formeterol and salbutamol?
Salmeterol
How does formeterol work?
Forms depot in lipid membrane and leaches out to interact with receptor
How does solmeterol work?
Interacts with the membrane and diffuses laterally to bind receptor
What do beta agonists inhibit?
Contraction of airway smooth muscle
What is theophylline?
PDE inhibitor
What does PDE do?
Inactivates cAMP
What does inhbition of PDE do?
Leads to increased cAMP which causes bronchodilation
What causes excitatory airway tone?
ACh(M3 receptors)
eNANC
What causes inhibitory airway tone?
Adrenaline
iNANC
NO
Ach (M2 receptors)
