Montelukast, used in asthma management, blocks the cysteinyl leukotriene receptor (CysLT1). Which leukotrienes are the primary ligands of this receptor?
- A LTB4
- B LTA4 and LTB4
- C LTC4, LTD4, and LTE4 ✓
- D LTC4 only
Correct answer: C. LTC4, LTD4, and LTE4
Explanation
Cysteinyl leukotrienes LTC4, LTD4, and LTE4 (formerly slow-reacting substance of anaphylaxis) act on CysLT1 receptors to cause bronchoconstriction, mucus secretion, and increased vascular permeability. LTB4 is a potent neutrophil chemoattractant acting on BLT receptors. Zileuton inhibits 5-LOX upstream.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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