endogenous pyrogen


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pyrogen

 [pi´ro-jen]
an agent that causes fever; called also pyretic and pyrectic. adj., adj pyrogen´ic.
endogenous pyrogen a low-molecular-weight protein that is produced by phagocytic leukocytes in response to stimulation by exogenous pyrogens and released into the circulation; it induces fever by acting on the preoptic area of the hypothalamus to raise the set-point of the hypothalamic thermostat. The pyrogen produced by monocytes and macrophages is not identical to that produced by neutrophils and eosinophils; the mononuclear phagocytes also produce a greater amount of pyrogen for a longer period of time than do the polymorphonuclear cells.
exogenous p's fever-producing agents of external origin, e.g., bacterial endotoxins and other microbial products, antigen-antibody complexes, viruses and synthetic polynucleotides, incompatible blood and blood products, and androgen breakdown products such as etiocholanolone; the action is mediated by endogenous pyrogen.

en·dog·e·nous py·ro·gen (EP),

proteins that induce fever. Several (about 11) have been identified, including cytokines formed by components of the immune system, especially macrophages (for example, interleukins 1 and 6, interferons, and tumor necrosis factors).
Synonym(s): leukocytic pyrogens

endogenous pyrogen

Any of a number of compounds, usually cytokines (e.g., interleukin-6, interleukin-1 alpha, tumour necrosis factor-alpha, interferon-gamma and macrophage inflammatory protein-1), that induce a febrile reaction, typically in a background of an acute-phase response.

en·dog·e·nous py·ro·gen

(EP) (en-doj'ĕ-nŭs pī'rō-jen)
An endogenous protein that induces fever. Several (about 11) have been identified, including cytokines formed by components of the immune system, especially macrophages (e.g., interleukins 1 and 6, interferons, and tumor necrosis factors).
Compare: bioregulator

en·dog·e·nous py·ro·gen

(en-doj'ĕ-nŭs pī'rō-jen)
Protein that induces fever.