Activated macrophages produce a gaseous mediator that causes vasodilation and contributes to microbicidal activity. This mediator is:
- A Nitric oxide ✓
- B Histamine
- C Prostaglandin E2
- D Leukotriene B4
Correct answer: A. Nitric oxide
Explanation
Nitric oxide is produced by nitric oxide synthase in macrophages. It causes vasodilation and reacts with superoxide to form peroxynitrite, a cytotoxic radical. Prostaglandin E2 and histamine are not gaseous, and leukotriene B4 is a chemoattractant without vasodilatory properties.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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