title: In vitro evidence of glucose-induced toxicity in GnRH secreting neurons: high glucose concentrations influence GnRH secretion, impair cell viability, and induce apoptosis in the GT1-1 neuronal cell line.
abstract: OBJECTIVE
  To evaluate for direct toxic effects of high glucose concentrations on cellular physiology in GnRH secreting immortalized GT1-1 neurons.
  
  
  METHODS
  Prospective experimental design.
  
  
  METHODS
  In vitro experimental model using a cell culture system.
  
  
  METHODS
  GT1-1 cells were cultured in replicates in media with two different glucose concentrations (450 mg/dL and 100 mg/dL, respectively) for varying time intervals (24, 48, and 72 hours).
  
  
  METHODS
  Effects of glucose concentrations on GnRH secretion by the GT1-1 neurons were evaluated using a static culture model. Cell viability, cellular apoptosis, and cell cycle events in GT1-1 neurons maintained in two different glucose concentrations were assessed by flow cytometry (fluorescence-activated cell sorter) using Annexin V-PI staining.
  
  
  RESULTS
  Adverse influences of high glucose concentrations on GnRH secretion and cell viability were noted in cultures maintained in high glucose concentration (450 mg/dL) culture medium for varying time intervals. A significantly higher percentage of cells maintained in high glucose concentration medium demonstrated evidence of apoptosis by a fluorescence-activated cell sorter.
  
  
  CONCLUSIONS
  We provide in vitro evidence of glucose-induced cellular toxicity in GnRH secreting GT1-1 neurons. Significant alterations in GnRH secretion, reduced cell viability, and a higher percentage of apoptotic cells were observed in GT1-1 cells maintained in high (450 mg/dL) compared with low (100 mg/dL) glucose concentration culture medium.
authors.affiliation: Department of Obstetrics, Gynecology & Women's Health, Albert Einstein College of Medicine, Bronx, New York, USA. lubnapal@aol.com
authors.forename: Lubna
authors.initials: L
authors.lastname: Pal
authors.forename: Hsiao-Pai
authors.initials: HP
authors.lastname: Chu
authors.forename: Jun
authors.initials: J
authors.lastname: Shu
authors.forename: Ilir
authors.initials: I
authors.lastname: Topalli
authors.forename: Nanette
authors.initials: N
authors.lastname: Santoro
authors.forename: George
authors.initials: G
authors.lastname: Karkanias
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D002460:Cell Line; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000633:toxicity*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D051379:Mice; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D011446:Prospective Studies
chemical_list: D007987:Gonadotropin-Releasing Hormone; D005947:Glucose