Mediators of Acute Inflammation: Histamine and Serotonin

Acute inflammation is a rapid response to tissue injury, infection, or other harmful stimuli. Among the crucial mediators of this process, histamine and serotonin play pivotal roles in modulating vascular and cellular reactions.

Histamine: The Early Responding Mediator

Histamine is primarily stored in mast cells, basophils, and platelets. It is released upon tissue injury, allergic reactions, or immune responses. Once released, histamine:

• Increases vascular permeability, leading to tissue swelling.
• Triggers vasodilation, resulting in redness and heat.
• Stimulates sensory nerve endings, causing itching and pain.
• Plays a role in bronchoconstriction during allergic responses.

Serotonin: A Multifaceted Inflammatory Modulator

Serotonin, predominantly found in platelets, acts as a neurotransmitter and inflammatory mediator. Its functions in inflammation include:

• Regulating vascular tone and promoting vasoconstriction.
• Enhancing platelet aggregation, contributing to clot formation.
• Modulating immune cell responses in tissue inflammation.

Conclusion

The interplay between histamine and serotonin in acute inflammation is essential for coordinating the body's defense mechanisms. Understanding their roles helps in developing therapeutic interventions for inflammatory disorders, allergies, and vascular diseases.