title: The activation of carrageenan air pouch inflammation by silica and its effects on cartilage degradation.
abstract: We have examined the effects of carrageenan inflammation activated by silica particles on implanted femoral-head cartilage. The injection of silica particles modifies the inflammatory response, inducing a prolonged polymorphonuclear leucocyte infiltration and low exudate volume. This modification in the inflammatory response resulted in an accelerated loss of proteoglycan by the implanted femoral heads. Examination of exudate interleukin 1 (IL-1) concentrations directly by a lymphocyte-activating assay and indirectly by measuring the acute-phase response indicated that the increased loss was not due to increased levels of IL-1. High levels of lactate dehydrogenase would suggest that the increase cartilage breakdown is due to dying polymorphonuclear leucocytes releasing their intracellular enzymes. It is concluded that injection of silica together with carrageenan produces a pathological environment similar to that seen in human septic arthritis.
authors.affiliation: Department of Pharmacology, Royal Veterinary College, Hatfield, Herts., United Kindgom.
authors.forename: A D
authors.initials: AD
authors.lastname: Sedgwick
authors.forename: R
authors.initials: R
authors.lastname: Hooke
authors.forename: J
authors.initials: J
authors.lastname: Dawson
authors.forename: P
authors.initials: P
authors.lastname: Lees
mesh_terms: D000818:Animals; D002351:Carrageenan; D002356:Cartilage / Q000032:analysis / Q000503:physiopathology*; D007249:Inflammation / Q000139:chemically induced / Q000503:physiopathology*; D007375:Interleukin-1 / Q000032:analysis; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D007963:Leukocytes, Mononuclear / Q000032:analysis; D008297:Male; D009113:Muramidase / Q000032:analysis; D009504:Neutrophils / Q000032:analysis; D010007:Osteochondritis; D011509:Proteoglycans / Q000032:analysis; D051381:Rats; D012822:Silicon Dioxide / Q000494:pharmacology*
chemical_list: D007375:Interleukin-1; D011509:Proteoglycans; D012822:Silicon Dioxide; D002351:Carrageenan; D007770:L-Lactate Dehydrogenase; D009113:Muramidase