title: Gene expression of bone-resorbing cytokines in rat osteolysis model.
abstract: Osteolysis after single-injection polyethylene (PE) administration has been analyzed, but this experimental model did not reflect the clinical postoperative condition. Therefore, we investigated the bone-resorbing cytokines interleukin and tumor necrosis factor (IL-1alpha, IL-6, TNFalpha) produced by continuous PE administration using histomorphologic findings and the reverse transcription polymerase chain reaction. TNFalpha mRNA was continuously detected in the PE continuous-infusion group, whereas it was not expressed in the PE single-injection group. IL-1alpha and IL-6 mRNA were detected in both groups. As for histomorphological findings, in the PE continuous-infusion group proliferating fibrous tissue penetrated subchondral bone and the interface membrane around the K-wire inserted into the femur. Numerous osteoclasts were observed in the vicinity of resorbed bone. In the PE single-injection group, proliferation of fibrous tissue with bone resorption was not observed. TNFalpha may play a major role in fibrous tissue formation and osteoclastic bone resorption caused by PE debris. This osteolysis model is useful for investigating osteolysis associated with bone-resorbing cytokines under conditions similar to those seen with a human prosthesis.
authors.affiliation: Department of Orthopaedic Surgery, Tokyo Women's Medical College, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Kang Jung
authors.initials: KJ
authors.lastname: Kim
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Itoh
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D015870:Gene Expression; D007150:Immunohistochemistry; D007375:Interleukin-1 / Q000235:genetics*; D015850:Interleukin-6 / Q000235:genetics*; D010014:Osteolysis / Q000209:etiology*; D020959:Polyethylene; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
chemical_list: D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D020959:Polyethylene