प्रश्न 38: निम्नलिखित में से कौन सा शोथ (इन्फ्लेमेशन) का पूर्व-निर्मित (प्रीफॉर्म्ड)... - पशु सूक्ष्मजीव विज्ञान, प्रतिरक्षा, विकृति विज्ञान एवं परजीवी विज्ञान - आईसीएआर एआईईईए पीजी 14 जुलाई 2023 (शिफ्ट 1) - पशु चिकित्सा विज्ञान | Agrigyan

Chemical mediators of inflammation are divided into preformed and newly synthesized:

• Preformed mediators: Stored in pre-packaged cytoplasmic secretory granules of cells, ready for immediate release upon stimulation. Histamine (stored in mast cell and basophil granules) and Serotonin (stored in platelets) are classic preformed mediators that cause immediate vasodilation and increased vascular permeability.
• Newly synthesized (de novo) mediators: Produced upon cell stimulation from arachidonic acid metabolites and membrane lipids; these include Leukotrienes, Prostaglandins, and Platelet Activating Factor (PAF).
• Plasma-derived mediators: Membrane Attack Complex (MAC) is assembled enzymatically downstream through complement cascade activation.
  
  Option analysis:
• (Histamine): Correct. Histamine is preformed and stored in mast cell granules.
• (Leukotrienes): Newly synthesized via lipoxygenase pathway from arachidonic acid.
• (Platelet activation factor): Newly synthesized from membrane phospholipids.
• (The membrane attack complex): Assembled downstream from plasma precursors.