[Induction of arthritis in the ankles of rat immunized by intraperitoneally-injected lipopolysaccharide (LPS) or lipid A].
The histological changes in the ankle joints were investigated in Sprague Dawley (SD) rat immunized through intraperitoneal injection of 10 micrograms or 100 micrograms of lipopolysaccharide(LPS; extracted from Escherichia coli), or Lipid A, for 10 or 15 weeks (short term) or for 30 weeks (long term). The serum anti-IgM rheumatoid factor-like substance (RFLS) was detected by enzyme-linked immunosorbent assay (ELISA). The macroscopic arthritic changes in the rat ankles, showing redness or swelling, were observed in 17 of 64 rats immunized by LPS and in 9 of 62 rats immunized by Lipid A. Rats immunized by 10 micrograms of LPS in the long term developed synovial lining cell hyperplasia in 12 of 28 ankles (12/28), lymphoid cell infiltration in 8/28, and pannus formation in 2/28. Rats immunized by 100 micrograms of Lipid A in the long term developed synovial lining cell hyperplasia in 8/18, lymphoid cell infiltration in 7/18, and pannus formation in 2/18. SD rats immunized by LPS or Lipid A developed a significantly higher incidence rate of hyperplasia in the synovial lining cells, than controls. In each case of immunization by LPS or Lipid A, the serum RFLS levels at sacrifice were significantly higher than before immunization (p < 0.01). These findings suggest that LPS and Lipid A played important roles as trigger substances causing arthritis with RFLS elevation in rats immunized with E. coli.
Suzuki
K
K
Department of Orthopedic Surgery, Yokohama City University School of Medicine, Kanagawa, Japan.
D000818:Animals; D000843:Ankle Joint; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D005260:Female; D007274:Injections, Intraperitoneal; D008050:Lipid A / Q000008:administration & dosage / Q000276:immunology*; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000276:immunology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012217:Rheumatoid Factor / Q000032:analysis; D013583:Synovial Membrane / Q000473:pathology
D008050:Lipid A; D008070:Lipopolysaccharides; D012217:Rheumatoid Factor