Continuous endotoxin infusion suppresses rat spleen cell production of cytokines.
Endotoxin, i.e., lipopolysaccharides, was continuously infused into rats at a nonlethal dose by means of an implanted osmotic pump for up to 2 weeks. The pump was connected to the jugular vein by a polyethylene catheter. Administration of endotoxin via the pump compromised the ability of spleen cells to produce the lymphokines interleukin 1 and tumor necrosis factor after stimulation in vitro with endotoxin. In addition, the ability of the spleen cells to produce alpha/beta-interferon in response to endotoxin in vitro was also examined, as was the capability of the spleen cells to produce gamma-interferon following stimulation with concanavalin A. Suppression of the expected interleukin 1 and tumor necrosis factor production by spleen cells from rats continuously infused with endotoxin was observed. There was also a moderate effect on interferon production, but this was much less. These results provide further findings indicating the unresponsiveness of spleen cells to lipopolysaccharides, as well as to a nonspecific plant mitogen, following continuous infusion of endotoxin into rats via an implanted osmotic pump. Additional studies are needed to determine the mechanisms involved in such suppression.
Friedman
H
H
Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa 33612.
Newton
C
C
Widen
R
R
Klein
T W
TW
Spitzer
J A
JA
D000818:Animals; D003208:Concanavalin A; D016207:Cytokines / Q000096:biosynthesis*; D004731:Endotoxins / Q000633:toxicity*; D007372:Interferons / Q000096:biosynthesis; D007375:Interleukin-1 / Q000096:biosynthesis; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016207:Cytokines; D004731:Endotoxins; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D003208:Concanavalin A; D007372:Interferons