title: [Effect of insulin on VEGF expression in bovine retinal microvascular endothelial cells exposed to normal or high glucose].
abstract: OBJECTIVE
  To investigate the effect of insulin or (and) high glucose on the vascular endothelial growth factor (VEGF) expression in bovine retinal microvascular endothelial cells (BREC).
  
  
  METHODS
  It was a experimental study. BREC were cultured with selective culture media. Passaged cells were cultured in normal (5 mmol/L) or high glucose (30 mmol/L) medium for 3 days. Equimolar mannitol was supplemented for osmotic controls. Cells were serum-deprived overnight in Dulbecco's modified Eagle's medium containing 0.2% w/v bovine serum albumin and then incubated in the absence or presence of 100 nmol/L insulin for 24 hrs. Cells were harvested and the expression of VEGF mRNA was analyzed by Real-time PCR. VEGF protein level was determined by HUVEC proliferation assay, immunofluorescence and western-blot
  
  
  RESULTS
  Insulin or (and) high glucose significantly increased VEGF mRNA (F = 5.67, 9.04; P <0.05) and protein (F = 5.50, 5.57; P <0.05) expression. However, the combined effect of insulin and high glucose is weak in contrast to insulin or high glucose alone.
  
  
  CONCLUSIONS
  High glucose attenuated insulin-induced VEGF expression. Therefore, VEGF may be not the major factor that lead to transient worsening of diabetic retinopathy after acute insulin therapy in diabetes.
authors.affiliation: Department of Ophthalmology, Shanghai Jiao Tong University Affiliated First People's Hospital, Shanghai, China.
authors.forename: Hai-Xiang
authors.initials: HX
authors.lastname: Wu
authors.forename: Xin
authors.initials: X
authors.lastname: Xia
authors.forename: Kun
authors.initials: K
authors.lastname: Liu
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zheng
authors.forename: Dong-Qing
authors.initials: DQ
authors.lastname: Zhu
authors.forename: Xun
authors.initials: X
authors.lastname: Xu
authors.forename: Qing
authors.initials: Q
authors.lastname: Gu
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D012171:Retinal Vessels / Q000166:cytology / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D007328:Insulin; D042461:Vascular Endothelial Growth Factor A; D005947:Glucose