pyrogen

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.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

py·ro·gen

(pī'rō-jen),

A fever-inducing agent; pyrogens are produced by bacteria, molds, viruses, and yeasts.

[pyro- + G. -gen, producing]

Farlex Partner Medical Dictionary © Farlex 2012

pyrogen

(pī′rə-jən)

n.

A substance that produces fever.

The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

pyrogen

 A fever-inducing substance

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

py·ro·gen

(pī'rō-jen)

A fever-inducing agent; produced by bacteria, molds, viruses, and yeasts; commonly found in distilled water.

[pyro- + G. -gen, producing]

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

pyrogen

Any substance that causes fever. Endogenous pyrogens are proteins, such as interleukin-1, released by white blood cells in response to bacterial or viral infections. These act on the temperature-regulating centre in the brain, effectively resetting the thermostat at a higher level and causing the muscles to contract repeatedly and rapidly (shivering) so as to raise body temperature.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

pyrogen

any substance which alters the body thermostat of HOMOIOTHERMS to a higher setting, giving rise to fever.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

Pyrogen

A chemical circulating in the blood that causes a rise in body temperature.

Mentioned in: Fever

Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

py·ro·gen

(pī'rō-jen)

Fever-inducing agent; produced by bacteria, molds, viruses, and yeasts.

[pyro- + G. -gen, producing]

Medical Dictionary for the Dental Professions © Farlex 2012