Chemical mediators of inflammation

Chemical mediators account for the events of inflammation. Inflammation has the following sequence:

Cell injury _____ Chemical mediators ______ Acute inflammation (i.e. the vascular & cellular events).

 Sources of mediators:

The chemical mediators of inflammation can be derived from plasma or cells.

 a) Plasma-derived mediators:

        i) Complement activation 

-  increases vascular permeability (C3a,C5a)

-  activates chemotaxis (C5a)

- opsonization (C3b,C3bi)

         ii) Factor XII (Hegman factor) activation

Its activation results in recruitment of four systems: the kinin, the clotting, the fibrinolytic and the compliment systems.

 b) Cell-derived chemical mediatos: 

Cell-derived chemical mediators include:

- Most mediators perform their biologic activities by initially binding to specific receptors on target cells. Once activated and released from the cells, most of these mediators are short lived. Most mediators have the potential to cause harmful effects.

References

Bezabeh ,M. ; Tesfaye,A.; Ergicho, B.; Erke, M.; Mengistu, S. and Bedane,A.; Desta, A.(2004). General Pathology. Jimma University, Gondar University Haramaya University, Dedub University.