Cellemidler

Cellemidler, or cell mediators, are substances produced and released by cells that influence the behavior of other cells. They function as signaling molecules in a range of physiological processes, including inflammation, immunity, and tissue repair. Mediators can act locally (autocrine or paracrine signaling) or travel through body fluids (endocrine signaling).

Categories of cellemidler include lipid mediators, peptide mediators, and small molecules. Lipid mediators such as prostaglandins, leukotrienes, and platelet-activating factor derive from membrane lipids and modulate vascular tone, permeability, and leukocyte recruitment. Peptide mediators comprise cytokines (for example interleukins and interferons), chemokines, and growth factors (such as VEGF and TGF-β), which coordinate cell proliferation, differentiation, and immune responses. Other examples include histamine released from mast cells, serotonin from platelets, and nitric oxide produced by endothelial and immune cells, all of which can influence blood flow, permeability, and signaling.

Cellemidler participate in countless physiological responses, from defending against infections to promoting wound healing. Their actions are mediated through specific receptors on target cells, triggering signaling cascades and gene expression changes. Dysregulation of mediators can contribute to pathological conditions, including chronic inflammation, allergy, autoimmune diseases, and cancer.

In research and medicine, the measurement and modulation of cell mediators are central to understanding disease mechanisms and developing therapies. Treatments may target individual mediators or their receptors, such as antihistamines blocking histamine receptors or monoclonal antibodies against particular cytokines.