title: Influence of intradiscal medication on nucleus pulposus cells.
abstract: BACKGROUND
  Eugene Carragee was the first to prove that provocative discography may contribute to intervertebral disc degeneration. Disc degeneration can be induced either by mechanical trauma caused by the puncturing needle or as a pharmacological effect of the drugs instilled into the disc.
  
  
  OBJECTIVE
  The aim of this study was to test the influence of cortisone, lidocaine, and iopamidol on nucleus pulposus cells under an in vitro setting.
  
  
  METHODS
  Controlled in vitro study is the design type.
  
  
  METHODS
  The nucleus pulposus was excised from 12 bovine tail intervertebral discs and monolayer cell cultures were generated. The cultures were divided into four sample groups and incubated in either standard cell culture medium (control group) or medium supplemented with the test substances. The dose rate was adapted based on a total dose of 3 mL iopamidol, 1 mL lidocaine, and 10 mg cortisone per nucleus pulposus. Cell count, viability, proliferation, and differentiation features were analyzed. The study was supported by DePuy. No conflicts of interest arise from this support.
  
  
  RESULTS
  After 24 hours, a significant decrease in cell counts was observed in all three test groups. Population doubling time was 16 hours in the control group cultured in standard medium and increased to 21 hours (cortisone), 25 hours (iopamidol), and 38 hours (lidocaine) after incubation in discography medication (p<.001). Cell viability was slightly, but not significantly decreased in all medication groups. Cells incubated in Lidocaine were significantly smaller (p<.01) and showed clearly reduced pseudopodia formation. Incubation in lidocaine and iopamidol also significantly reduced glycosaminoglycan synthesis.
  
  
  CONCLUSIONS
  Although only a small decrease in cell viability was observed in all three substances tested, cell count and proliferation decreased significantly. Incubation in lidocaine inhibited pseudopodia formation and might therefore interfere with intercellular signalling and cell migration. Glycosaminoglycan synthesis was significantly decreased after contact with lidocaine as well as Iopamidol. These observations suggest that all three medications tested might interfere with biological repair mechanisms of the intervertebral disc and therefore contribute to a further degeneration.
authors.affiliation: Orthopädisches Spital Speising, 3. Orthopädische Abteilung, Speisinger Str. 109, 1130 Wien, Austria. Electronic address: claudia.eder@oss.at.
authors.forename: Claudia
authors.initials: C
authors.lastname: Eder
authors.forename: Astrid
authors.initials: A
authors.lastname: Pinsger
authors.forename: Sabrina
authors.initials: S
authors.lastname: Schildboeck
authors.forename: Erwin
authors.initials: E
authors.lastname: Falkner
authors.forename: Philipp
authors.initials: P
authors.lastname: Becker
authors.forename: Michael
authors.initials: M
authors.lastname: Ogon
mesh_terms: D000818:Animals; D002417:Cattle; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003348:Cortisone / Q000494:pharmacology*; D007403:Intervertebral Disc / Q000166:cytology / Q000187:drug effects*; D007479:Iopamidol / Q000494:pharmacology*; D008012:Lidocaine / Q000494:pharmacology*
chemical_list: D008012:Lidocaine; D007479:Iopamidol; D003348:Cortisone
keywords: Discography; Intradiscal medication; Iopamidol; Lidocaine; Triamcinolonacetonid