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.
Department of Medical Microbiology and Immunology, University of South Florida College of Medicine, Tampa 33612.
H
H
Friedman
C
C
Newton
R
R
Widen
T W
TW
Klein
J A
JA
Spitzer
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