Introduction

Inflammatory mediators are a class of molecules and cellular components that are released by cells in response to inflammation. They are responsible for the initiation, propagation, and resolution of inflammation. Inflammation is a necessary process for the body to respond to tissue damage and infection, and the inflammatory mediators play a key role in this process. In this review, we will discuss the different types of inflammatory mediators and how they act in the physiology of inflammation.

Types of Inflammatory Mediators

Inflammatory mediators can be divided into two main categories: cytoplasmic mediators and cell-surface mediators. Cytoplasmic mediators are released from the cytoplasm of cells and include cytokines, chemokines, and prostaglandins. Cell-surface mediators are released from the cell membrane and include leukotrienes, platelet-activating factor, and histamine.

Cytoplasmic Mediators

Cytokines are proteins that are released by cells in response to inflammation. They act as signaling molecules, helping to regulate the body's immune response. Examples of cytokines include interleukins, interferons, and tumor necrosis factor (TNF).

Chemokines are small proteins that act as chemoattractants, meaning they help to direct the movement of cells to the site of inflammation. Examples include chemokine (C-X-C motif) ligand 1 (CXCL1) and chemokine (C-C motif) receptor 2 (CCR2).

Prostaglandins are lipid molecules that are released by cells in response to inflammation. They act as signaling molecules, helping to regulate the body's response to inflammation. Examples include prostaglandin E2 (PGE2) and prostaglandin I2 (PGI2).

Cell-Surface Mediators

Leukotrienes are lipids that are released from the cell membrane in response to inflammation. They act as signaling molecules, helping to regulate the body's response to inflammation. Examples include leukotriene B4 (LTB4) and leukotriene C4 (LTC4).

Platelet-activating factor (PAF) is a lipid molecule that is released from the cell membrane in response to inflammation. It acts as a potent signaling molecule, helping to regulate the body's response to inflammation.

Histamine is a small molecule that is released from the cell membrane in response to inflammation. It acts as a signaling molecule, helping to regulate the body's response to inflammation.

Physiological Role of Inflammatory Mediators

Inflammatory mediators play a key role in the body's response to inflammation. They are responsible for the initiation, propagation, and resolution of inflammation.

Initiation of Inflammation

The release of inflammatory mediators is the first step in the inflammatory response. Cytokines, chemokines, and prostaglandins are released from cells in response to tissue damage or infection, and these molecules act as signaling molecules, helping to initiate and propagate the inflammatory response.

Propagation of Inflammation

The inflammatory mediators help to propagate the inflammatory response by recruiting additional cells to the site of inflammation. Chemokines act as chemoattractants, helping to direct the movement of cells to the site of inflammation. Platelet-activating factor (PAF) helps to activate platelets, which are important in clot formation and the recruitment of additional cells.

Resolution of Inflammation

The inflammatory mediators also play a role in the resolution of inflammation. Prostaglandins help to inhibit the inflammatory response by reducing the production of cytokines and chemokines. Leukotrienes act as antagonists of cytokines and chemokines, helping to decrease the intensity of the inflammatory response. Histamine helps to reduce the intensity of the inflammatory response by inhibiting the production of pro-inflammatory cytokines.

Conclusion

Inflammatory mediators are a class of molecules and cellular components that are released by cells in response to inflammation. They are responsible for the initiation, propagation, and resolution of inflammation. The different types of inflammatory mediators include cytokines, chemokines, prostaglandins, leukotrienes, platelet-activating factor, and histamine. These molecules play a key role in the body's response to inflammation, helping to initiate, propagate, and resolve the inflammatory response.