2.13 Messenger Lipid: Eicosanoids

• Eicosanoid

  • Lipid-based signaling molecules that play a unique role in innate immune responses.
  • Have profound physiological effects at extremely low concentrations.
  • Are hormone-like molecules
  • Exert their effects in the tissues where they are synthesized.
  • Usually has a very short "life".
• Physiological Effects of Eicosanoids:

  1. Inflammatory response
  2. Production of pain and fever
  3. Regulation of blood pressure
  4. Induction of blood clotting
  5. Control of reproductive functions, such as induction of labor
  6. Regulation of the sleep / wake cycle
• Principle types of Eicosanoids:

  1. Prostaglandin
  2. Thromboxane
  3. Leukotriene
• Prostaglandin

  • C20-fatty-acid derivative containing cyclopentane ring and oxygen-containing functional groups.
  • Raising body temperature
  • Inhibiting the secretion of gastric juices
  • Increasing the secretion of a protective mucus layer into the stomach
  • Relaxing and contracting smooth muscle
  • Directing water and electrolyte balance
  • Intensifying pain and enhancing inflammation responses
• Thromboxane

  • C20-fatty-acid derivative containing a cyclic ether ring and oxygen-containing functional groups.
  • Promotes platelet aggregation.
• Leukotriene

  • C20-fatty-acid derivative containing three conjugated double bonds and hydroxyl groups.
  • Promote inflammatory and hypersensitivity (allergy) responses.