Responses of baboons to traditionally pyrogenic agents

It is not clear whether baboons develop fever in response to endotoxin or other pyrogens. We injected various pyrogens intravenously in 12 unrestrained baboons (Papio ursinus) and measured their body temperature using intra-abdominal radio-telemeters. Serum ion concentration was also measured. The baboons developed fever after injection of killed Staphylococcus aureus (5 x 10⁷ organisms/kg). No significant fever was measured after injection of lipopolysaccharide (Salmonella typhosa) (0.1, 8, 40, and 100 μg/kg), bovine serum albumin (4 mg/kg), killed Salmonella minnesota (5 x 10⁷ organisms/kg), and killed Salmonella typhi (5 x 10⁷ organisms/kg). A significant decrease in serum iron concentration was found only after injection of S. aureus and lipopolysaccharide, 100 μg/kg. The phagocytic synthesis of interleukin-1 following pyrogen stimulation in baboons and some other primates appears to differ from that in man and in nonprimates.