Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Glossary of acronyms
- 1 Fever – definition, usefulness, ubiquity
- 2 Thermoregulation – an outline
- 3 The nature of pyrogens, their origins and mode of release
- 4 The loci of action of endogenous mediators of fever
- 5 Beyond the loci of action of circulating pyrogens: mediators and mechanisms
- 6 The role of the cerebral cortex, the limbic system, peripheral nervous system and spinal cord, and induced changes in intracranial pressure
- 7 Antipyresis
- 8 Febrile convulsions in children and a possible role for vasopressin
- 9 A synthesis, predictions and speculations from my armchair
- Appendix 1 Anatomical considerations
- References
- Index
3 - The nature of pyrogens, their origins and mode of release
Published online by Cambridge University Press: 10 September 2009
- Frontmatter
- Contents
- Preface
- Acknowledgements
- Glossary of acronyms
- 1 Fever – definition, usefulness, ubiquity
- 2 Thermoregulation – an outline
- 3 The nature of pyrogens, their origins and mode of release
- 4 The loci of action of endogenous mediators of fever
- 5 Beyond the loci of action of circulating pyrogens: mediators and mechanisms
- 6 The role of the cerebral cortex, the limbic system, peripheral nervous system and spinal cord, and induced changes in intracranial pressure
- 7 Antipyresis
- 8 Febrile convulsions in children and a possible role for vasopressin
- 9 A synthesis, predictions and speculations from my armchair
- Appendix 1 Anatomical considerations
- References
- Index
Summary
In the aphorisms of Sanctorious (Lister, 1701 in Sanctorii Sanctorii, 1701) we read ‘In febribus intermittentibus cur perspiratio insensibilis prohibetur? quia humor peccans est in ambitu corporis’ In other words ‘Why is insensible perspiration (the term then for sweating) stopped in fever? because an evil humour circulates in the body’. This may be the earliest mention, in ignorance, of what we now call an endogenous pyrogen.
We now define a pyrogen as a substance which when introduced into the circulation, or given intracerebrally, causes the symptoms and consequences of fever, namely a rise in body temperature which at its plateau behaves as though the temperature is regulated, and which is brought about by a combination of heat retention processes and increased metabolic rate. The process which we have defined as fever is now thought to be but one part of a complex host defence reaction involving not only a rise in temperature but activation of many immune responses and processes for the destruction of micro-organisms. This process is termed the acute phase response. Pyrogens as defined above must be differentiated from substances which just affect the metabolic rate such as dinitro-ortho-cresol, or which cut down heat loss such as adrenergic agonists, but which do not induce the acute phase response. The rise in temperature caused by such agents should be termed hyperthermia, not fever, and the agents should be termed hyperthermic agents not pyrogens.
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- Fever and AntipyresisThe Role of the Nervous System, pp. 36 - 46Publisher: Cambridge University PressPrint publication year: 1995