Introduction
Inflammation and healing has been a consistently evident process throughout human life. The uncomfortable feeling or pain one gets soon after an injury is because of the process of inflammation, which further induces healing and repair. This process of inflammation from the site of injury is carried out through the inflammatory mediators. Inflammatory mediators are cells of the body’s defense mechanism, such as neutrophils, lymphocytes, and monocytes (these are different types of white blood cells). Inflammation is the body’s response to any physical or chemical harm happening in the body. Inflammation activated at the injured site can be either acute or chronic, depending upon the longevity of the problem. Depending on whether it is an acute or chronic inflammation, different sets of mediators are released in the system.
What Are the Types of Inflammation?
Inflammation is scientifically defined as the localized protective response of the body to any injury or destruction of the cellular tissues caused by physical, immunological, chemical, or microbial factors. Inflammation can be classified into two types, namely:
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Acute Inflammation: Acute inflammation is the primary inflammation of the body that occurs immediately after wound healing. The inflammatory mediators from the sight of injury send signals to the brain, which in turn activate the events of inflammation.
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Chronic Inflammation: Chronic inflammation is a result of long-term illness; at the site of a long-term infection, the second line of inflammatory cells, like the lymphocytes and macrophages, send signals acting as inflammatory receptors, activating the inflammatory mediators.
What Are Inflammatory Mediators?
Inflammatory mediators are chemical agents or molecules produced in the body, activated by the brain, which are released at the time of an infection or injury. The inflammatory mediators are produced by the systemic immunity cells like monocytes, lymphocytes, and neutrophils, which get modulated by agents like proteins, glycoproteins, peptides, cytokines, nitric oxide, arachidonic acid metabolites, and oxygen free radicals present in the body. The main function of these receptors is to initiate and release inflammatory immune responses required for healing and repair. Hence, the body releases inflammatory mediators, helping the body against any harmful stimulus by defending itself.
What Are the Types of Inflammatory Mediators?
Inflammatory mediators, on the whole, are multiple agents put together involving different body parts, and hence, the types of inflammatory mediators are:
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Cytokines: Cytokines release multiple inflammatory mediators like the tumor necrosing factors, interleukin - 1 to interleukin - 13, transforming growth factor - beta, granulocyte-macrophage colony-stimulating factor released for cells including the macrophages, lymphocytes, endothelial and epithelial cells. Here, the main purpose of these cytokines is to cause the release of prostaglandin, activating the inflammatory cells of the neutrophils, macrophages, and eosinophils, activating B and T cells showing fibroblastic and epithelial proliferation. Mimics the functions of immunoglobulins like IGA that are produced by b cell lymphocytes, increases production of eosinophils, and promotes chemotaxis of the eosinophils. The growth factor by the neutrophils increases the maturation of the inflammatory process by recruiting, activating, and proliferating new inflammatory cells.
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Chemokines: The chemokines comprise interleukin - 8, RANTES, histamine, MCP-1, vascular endothelial growth factor, and platelet-activating factor. These chemokines are sourced by macrophages, fibroblasts, epithelial cells, endothelial cells, mast cells, basophils, monocytes, lymphocytes, and neutrophils. The function of chemokines is the activation of chemotaxis, increasing vascular permeability, causing vasodilation and degradation of neutrophils.
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Mast Cells: Mast cells are derived from bone marrow cells, which are used for releasing mediators like tryptase and histamine and in the synthesis of mediators like prostaglandins and leukotrienes.
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Arachidonic Acid Metabolites: These arachidonic metabolites are classified into three agents, and they are:
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Prostaglandins: The prostaglandins are sourced from the neutrophils, mast cells, monocytes, and endothelial cells. Prostaglandins are responsible for vasodilation and mucus production and most of all, inhibit the sedimentation of platelets, resulting in clot formation.
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Leukotrienes: The leukotrienes include LTB, LTC, LTD, and LTE released from neutrophils, mast cells, and endothelial cells, which increases the vascular permeability, vasoconstriction, degranulation of neutrophils, and chemotaxis.
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Bradykinin: The bradykinesia are cells released from the plasma cells, which are responsible for increasing the onset and perception of pain and altering the vascular permeability.
What Are the Functions of Inflammatory Mediators?
Inflammatory mediators involved in a series of events from the onset of the inflammatory process to repair are mainly aimed at the body's healing, and some of the functions in the sequence of healing are:
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Alters the Vascular Permeability of the Cellular Membrane: As many times inflammation can be a breach in the cellular membrane, the immediate response of the body is to send more blood to the site of injury, where this concept of altered cell membrane takes place. If there is a breach in the cellular membrane, which can make the cell membrane weak, enchanting the inflow and outflow of inertial fluid, leading to more infection. To prevent all that, the inflammatory mediators activate the inflammatory cells, altering the permeability of the cell membrane.
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Initiate Chemotaxis: Chemotaxis, in other words, is the recognition of harmful agents like bacteria or cells through chemical enzymes released by these chemotactic cells. In chemotaxis, the cells migrate uniformly according to the inflammatory or extracellular signals that are received. The process of migration happens through a guided modulation provided by the chemotactic enzymes.
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Increases the Production of Mucous Glycoprotein: The mucus present in the body, secreted by the lymphatic components, acts as clearing agents that help in cleansing the system during any infection. Inflammatory regulators alter the secretion levels as well as the consistency of the normal mucus cells into the desired levels.
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Activates Other Biological Mediators: The other biological mediators (chemical substances) that are seen in other components of the immune system, like the cytokines, tumor necrosing factors, cancer predilection cells, etc., activate these cells that help and enhance the healing momentum of the body as well as by activating its cycle. The other biological mediator is the free radicals, as these cells bind at the site of injury and break the unwanted cells, activating faster healing.
Conclusion
Inflammation is a process of healing and the body's defense mechanism. The inflammatory mediators are the backbone of the inflammatory process as they synchronize the function in a very coordinated way. These inflammatory cells majorly contribute to all the parts of the body that undergo inflammation. These modulators modify according to each organ and their desired needs. However, the most important function is immediate action, protection, and enhancing healing.
