What is the Origin of Pyrogens?

The term is rooted in classical physiology, derived from Greek meaning "fire-producing," describing their observable effect of raising the body's core temperature set-point. Their identity was clarified with the study of bacterial endotoxins.

What is the Mechanism of Pyrogens?

Exogenous pyrogens, such as LPS, are recognized by immune cells, prompting the release of endogenous pyrogens like specific interleukins, particularly IL-1$beta$ and IL-6. These cytokines then act on the preoptic area of the hypothalamus to stimulate prostaglandin E2 synthesis, which resets the thermoregulatory thermostat upward.

Pyrogens ∞ Area

Pyrogens

Meaning

Pyrogens are substances, typically derived from microbial sources or generated internally by the immune system, that act directly upon the thermoregulatory center in the hypothalamus to induce a fever response. These agents signal a state of immunological challenge to the entire organism. They are potent modulators of systemic physiology.