Asthma Drug mechanisms

Question 1

Describe the mechansim of CysTL1 receptor angatonist

Answer 1

• Mast cells activated
• intracellular release if arachidonic acid
• 5-lipoxygenase convers A-acid into LTA4 which is further converted to LTB4 and LTC4
• transported from mast cell into intracellular space
• LTB₄ tiggers inflitration of further inflammatory cells into airway
• These cells release CysLTs
• LTC₄ is converted into LTD4 and LTE4
• all act on receptor and cause contraction
• CysLT₁ antagonist blocks this acition

Question 2

Describe the molecular mechanism of Glucocorticoids

Answer 2

• Nuclear receptor signalling - Lipophillic
• duffuse into cytoplasm and bind to GRa( usually combined with shock protien)
• this triggers dissociation of sockprotien
• the activted receptor travels to the nucleous via imporins
• monomer assembles into homodimer and binds to glococorticoid responce element in promoter region of gene
• increases translation of anti-inflammatory genes

Question 3

Action of LTD₄

Answer 3

• increases contration on ASM
• Triggers eosinophillic influx
• edema
• uncreased mucous secretion
• decreased mucoucillary clearance
• recruitment of inflmmatoy mediators
• therefore epitheilial damage