L16 Pharmacology of Respiratory Tract Flashcards
describe how SM contracts
stimulus –> Ca++ release –> Myosin +P –> thin filament/ thick filament engagement –> contraction (lattice collapse)
Describe how SM relaxes
stimulus withdrawal –> Ca++ uptake SR –> Myosin loses P –> thin filament/ thick filament disengagement –> relaxation (lattice normal shape)
What is the key messenger that helps to phosphorylate myosin?
cAMP (adds/removes Ca++)
What action does B2 agonists have on bronchioles
inc cAMP > inc protein kinase > inactivation MLCK > removal Ca++ > bronochodilation
increase of MCC
What are side effects of B2 agonsists
high doses might also target B1 so will see tachycardia, excitement, sweating
What is an example of a B2 agonist
Clenbuterol
What action do phosphodiesterase inhibitors have on bronchioles?
prevents the degradation of cAMP so > inactivates MLCK > BRONCHODILATION
- Inc HR & CO
- CNS stimulation
What are more effective, B agonists of phosphodiesterase inhibitors
B agonist
What are some effects phosphodiesterase inhibitors
CNS stimulation
diuresis
What is an example of a phosphodiesterase inhibitor
Theophylline
What action do muscarinic receptor antagonists have on bronchioles?
Parasympathetic stimulation causing bronchoconstriction via the M3 muscarinic receptors on bronchial SMs.
Airway relaxation
What has a more profound affect, B2 adrenergic agonists or muscarinic receptor antagonists (anticholinergics)
B2 !
Corticosteroids are what type of drug?
anti-inflammatory
repress expression of proteins controlling immunomodulatory genes that are elevated in asthma sufferers.
What is the best route of delivery for these drugs?
inhalation Generaly b/c more localised effects
what is the action of mucolytics
increase production of serious mucus in resp tract to make mucus thinner and less viscous to assist MCC
