Key Inflammatory Mediators

Inflammatory mediators are crucial players in the body’s response to injury and infection. Understanding these substances, like histamine and cytokines, helps nurses recognize symptoms and manage conditions related to inflammation effectively. This knowledge is key in patient care.

1. Histamine

   • Released by mast cells and basophils during allergic reactions and inflammation.
   • Causes vasodilation and increased vascular permeability, leading to redness and swelling.
   • Plays a key role in the allergic response and symptoms such as itching and hives.

2. Prostaglandins

   • Lipid compounds derived from arachidonic acid that mediate inflammation and pain.
   • Promote vasodilation and increase blood flow to injured tissues.
   • Involved in the regulation of fever and the inflammatory response.

3. Leukotrienes

   • Produced by leukocytes and play a significant role in allergic reactions and asthma.
   • Cause bronchoconstriction, increased vascular permeability, and attract immune cells to sites of inflammation.
   • Contribute to chronic inflammatory conditions.

4. Cytokines (e.g., IL-1, IL-6, TNF-α)

   • Signaling proteins that mediate and regulate immunity, inflammation, and hematopoiesis.
   • IL-1 and TNF-α are key mediators of the inflammatory response, promoting fever and acute phase reactions.
   • IL-6 is involved in the acute phase response and stimulates immune cell differentiation.

5. Bradykinin

   • A peptide that causes vasodilation and increases vascular permeability.
   • Plays a role in pain signaling and is involved in the inflammatory response.
   • Contributes to the symptoms of inflammation, such as swelling and pain.

6. Complement proteins

   • A group of proteins that enhance the ability of antibodies and phagocytic cells to clear pathogens.
   • Activate a cascade that leads to opsonization, inflammation, and cell lysis.
   • Play a crucial role in the innate immune response and inflammation.

7. Nitric oxide

   • A gaseous signaling molecule that causes vasodilation and increases blood flow to tissues.
   • Produced by endothelial cells and macrophages, playing a role in the immune response.
   • Involved in the regulation of inflammation and can have both pro-inflammatory and anti-inflammatory effects.

8. Platelet-activating factor (PAF)

   • A phospholipid mediator that promotes platelet aggregation and inflammation.
   • Increases vascular permeability and attracts leukocytes to sites of injury.
   • Plays a role in allergic reactions and anaphylaxis.

9. Serotonin

   • A neurotransmitter that also acts as a mediator in the inflammatory response.
   • Released by platelets during clotting and contributes to vasodilation and increased vascular permeability.
   • Involved in the regulation of mood, but also plays a role in pain perception during inflammation.

10. Substance P

    • A neuropeptide involved in the transmission of pain and the inflammatory response.
    • Released from sensory neurons and contributes to the sensation of pain and itch.
    • Plays a role in the regulation of immune responses and inflammation.