title: Time- and dose-dependent cytotoxicities of ioxitalamate and indigocarmine in human nucleus pulposus cells.
abstract: BACKGROUND
  Ioxitalamate (Telebrix 300) is an ionic iodinated contrast medium commonly used for discography or percutaneous endoscopic lumbar discectomy (PELD), though it has side effects such as anaphylactic shock and renal toxicity. Indigocarmine is an organic compound dye with a distinctive blue color that is commonly used during PELD to stain the acidic, degenerated nucleus pulposus (NP). Although ioxitalamate and indigocarmine are widely used in spinal surgery, there have been no reports on their effects on NP cells. We studied the toxicities of both ioxitalamate and indigocarmine to NP cells.
  
  
  OBJECTIVE
  To determine the toxicities of both ioxitalamate and indigocarmine to NP cells in vitro.
  
  
  METHODS
  In vitro, controlled study of the toxicities of both ioxitalamate and indigocarmine to human NP cells.
  
  
  METHODS
  Nucleus pulposus cells were obtained via discectomy from lumbar disc patients and isolated. Nucleus pulposus cells were cultured in three-dimensional (3D) alginate beads with 0.001, 0.1, 10, and 100 mg/mL ioxitalamate, 0.00001, 0.001, 0.1, and 10 mg/mL indigocarmine, or a mixture of both for 1, 2, or 3 days. The living cells were analyzed with trypan blue staining. Fluorescence Activated Cell Sorting analysis using Annexin V and propidium iodide and 3D alginate bead immunostaining was performed to identify live, apoptotic, and necrotic cells.
  
  
  RESULTS
  Ioxitalamate, indigocarmine, and their combination induced statistically significant NP cell injury that was both time- and dose dependent (p<.05). Also, at the same concentration, ioxitalamate was more cytotoxic than was indigocarmine or the combination (p<.05). All three treatments also showed dose-dependent cytotoxicity according to flow cytometry and immunostaining.
  
  
  CONCLUSIONS
  Ioxitalamate and indigocarmine are toxic to human NP cells in vitro in a time- and dose-dependent manner. We assume that ioxitalamate and indigocarmine may have similar effects in patients undergoing discography and PELD. Thus, we suggest that ioxitalamate and indigocarmine should be used carefully at low concentrations.
authors: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, 712 Eonjuro, Gangnam-gu, Seoul 135-720, South Korea.
authors: Kyung-Hyun
authors: KH
authors: Kim
authors: Young-Sung
authors: YS
authors: Kim
authors: Sung-Uk
authors: SU
authors: Kuh
authors: Hyo-Suk
authors: HS
authors: Park
authors: Jeong-Yoon
authors: JY
authors: Park
authors: Dong-Kyu
authors: DK
authors: Chin
authors: Keun-Su
authors: KS
authors: Kim
authors: Yong-Eun
authors: YE
authors: Cho
mesh_terms: D000328:Adult; D000368:Aged; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D004396:Coloring Agents / Q000008:administration & dosage / Q000633:toxicity*; D003287:Contrast Media / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007203:Indigo Carmine / Q000008:administration & dosage / Q000633:toxicity*; D007403:Intervertebral Disc / Q000187:drug effects*; D007483:Iothalamic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D055815:Young Adult
chemical_list: D004396:Coloring Agents; D003287:Contrast Media; D007483:Iothalamic Acid; C002587:ioxitalamic acid; D007203:Indigo Carmine