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TOLERANCE TO BACTERIAL PYROGENS : II. ROLE OF THE RETICULO-ENDOTHELIAL SYSTEM.
1Medical Service, Grady Hospital, and the Department of Medicine, Emory University School of Medicine, Atlanta.
Tolerance to bacterial pyrogens involves faster clearance from blood, with reticuloendothelial system (R-E) blockade impacting this process. This suggests a mechanism for developing unresponsiveness to pyrogenic substances.
Area of Science:
- Immunology
- Microbiology
- Pharmacology
Background:
- Bacterial pyrogens induce fever and tolerance.
- The mechanism of pyrogen tolerance is not fully understood.
Purpose of the Study:
- To investigate the mechanism of bacterial pyrogen tolerance.
- To determine the role of the reticuloendothelial system (R-E) in pyrogen tolerance.
Main Methods:
- Induction of pyrogen tolerance through repeated injections.
- Reticuloendothelial system (R-E) blockade using specific agents.
- Measurement of pyrogen clearance from circulating blood in rabbits.
- Testing for cross-tolerance between different bacterial species.
Main Results:
- R-E blockade reversed tolerance, increasing febrile response.
- Pyrogens cleared faster in tolerant animals compared to normal controls.
- Cross-tolerance observed, indicating non-specific pyrogen clearance.
- R-E blockade slowed pyrogen clearance in tolerant animals.
Conclusions:
- Pyrogen tolerance is associated with enhanced pyrogen clearance.
- The reticuloendothelial system (R-E) plays a role in pyrogen metabolism and tolerance.
- A non-specific mechanism contributes to the development of unresponsiveness to bacterial pyrogens.
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