Biochemical mediators are molecules that play a crucial role in transmitting signals within and between cells, tissues, and organs in the body. These signaling molecules are responsible for modulating a wide range of physiological processes, such as immune response, inflammation, tissue repair, and cell growth and differentiation. Some of the major types of biochemical mediators include:
- Cytokines: These are small, soluble proteins that are secreted by immune cells and other cell types. Cytokines regulate the immune response, inflammation, and cell communication. Examples include interleukins (ILs), interferons (IFNs), and tumor necrosis factors (TNFs).
- Chemokines: A subset of cytokines, chemokines are small, secreted proteins that primarily function in the recruitment and migration of immune cells to specific sites within the body. They play a vital role in immune response, inflammation, and tissue repair. Examples include CCL2 (also known as MCP-1) and CXCL8 (also known as IL-8).
- Growth factors: These are proteins that regulate cell growth, proliferation, differentiation, and survival. Growth factors bind to specific receptors on the surface of target cells, activating intracellular signaling pathways. Examples include epidermal growth factor (EGF), fibroblast growth factor (FGF), and vascular endothelial growth factor (VEGF).
- Hormones: Hormones are signaling molecules produced by glands in the endocrine system and released into the bloodstream. They regulate various physiological processes, such as metabolism, growth and development, and stress response. Examples include insulin, cortisol, and thyroid hormones.
- Eicosanoids: Eicosanoids are a group of lipid-based signaling molecules derived from arachidonic acid. They play a crucial role in inflammation, immune response, and the regulation of various physiological processes. Examples include prostaglandins, leukotrienes, and thromboxanes.
- Neurotransmitters: These are signaling molecules that transmit signals across synapses in the nervous system. They are responsible for transmitting nerve impulses between neurons, allowing for communication within the nervous system. Examples include acetylcholine, dopamine, and serotonin.
- Nitric oxide (NO): Nitric oxide is a small, gaseous molecule that functions as a signaling molecule in various physiological processes, such as vasodilation, immune response, and neurotransmission.
Biochemical mediators are essential for the proper functioning of the body, and their dysregulation can contribute to various pathological conditions, such as chronic inflammation, autoimmune diseases, and cancer. Understanding the role of these signaling molecules in physiology and disease can provide valuable insights into the development of new therapeutic strategies.