Which of the following inflammatory mediators is synthesized de novo and acts through nuclear factor-kappa B (NF-kB) activation rather than being preformed in granules?

• A Histamine
• B Serotonin
• C Heparin
• D Tumor necrosis factor-alpha (TNF-alpha) ✓

Explanation

TNF-alpha is synthesized de novo by activated macrophages (and other cells) via NF-kB-dependent transcription; it is not preformed in granules. TNF-alpha induces endothelial activation, fever, and systemic effects of inflammation. Histamine, serotonin, and heparin are preformed mediators stored in mast cell granules (histamine, serotonin) or mast cell/basophil granules (heparin), released rapidly by degranulation.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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