Inflammatory mediators Flashcards
What is the aim of inflammation?
Co-ordinate the movement of leukocytes and plasma proteins to the site of injury
Inflammation involves changes in two things and is coordinated by what?
Involves -
- Changes in blood vessels - vasodilation, increased permeability - maximise movement of WBC & plasma proteins to site of injury
- Changes in leukocytes - recruitment to site of injury.
Coordinated by chemical mediators
What are the 2 types of chemical mediators?
- Cell-derived - macrophages, endothelial cells
- Plasma protein-derived - bradykinin (kinin system), complement
What do cytokines do?
Upregulate the release of inflammatory mediators
How is harmful material removed?
Phagocytosis -
- Recognition and attachment of particle
- Engulfment of particle
- Killing or degradation of material
What are the general characteristics of inflammatory mediators?
- Short half life
- Vary in range of targets
- Can stimulate release of other mediators
What are the 8 classes of cell-derived inflammatory mediators?
- Vaso-active amines
- Arachidonic acid metabolites
- Platelet activating factor
- ROS
- NO
- Cytokines & chemokines
- Lysosomal constituents
- Neuropeptides
What are 2 examples of vaso-active amines?
Histamine & serotonin
What are the 2 pathways for arachidonic acid metabolites?
- Cyclooxygenase pathway
- Lipoxygenase pathway
What are 2 examples of cytokines/chemokines?
TNF & IL-1
What are the 2 plasma protein derived mediators?
Complement & coagulation systems
What are the two pathways of complement?
- Classical - antigens bound to microbe
- Alternative - microbe itself activates
What downstream effects does activation of C3 cause in complement?
- C3a - Recruitment & activation of WBC
- C3b – opsonin & activation of membrane attack complex
- C5-9 – membrane attack complex – punches hole in cell wall/membrane
