Paracrinos

Paracrinos refers to locally acting signaling molecules or mediators in some texts. The term is not widely standardized; in most peer-reviewed biology literature the term paracrine factors or paracrine signals is used.

Paracrine signaling involves cells secreting molecules that diffuse a short distance to affect neighboring cells, as opposed to autocrine (self-targeting) or endocrine (systemic) signaling. Paracrinos typically function via diffusion through the extracellular space and binding to specific receptors on nearby cells, initiating intracellular signaling cascades such as MAPK, PI3K-Akt, or JAK-STAT pathways.

Molecular types include growth factors (e.g., TGF-β, EGF), cytokines, chemokines, prostaglandins, and small molecules like nitric oxide. The effects are diverse: regulation of cell proliferation, differentiation, migration, immune responses, and tissue remodeling. In development and wound healing, paracrine signals coordinate patterning and repair; in cancer, they influence tumor growth and the tumor microenvironment.

Terminology: As a translational or multilingual variant, "paracrino" or "paracrinos" may appear in non-English sources; readers should consult the definition in the source. Mainstream nomenclature uses "paracrine." In scientific writing, if the term appears, it is prudent to verify whether it is intended to mean standard paracrine signaling or a specific usage defined by the author.