title: [Effects of low temperature exposure on dermal microvascular endothelial cells function].
abstract: OBJECTIVE
  To explore the damage effects and expression of vascular endothelial growth factor (VEGF) exposed with different low-temperatures on rat dermal microvascular endothelial cells (DMVECs).
  
  
  METHODS
  Primary DMVECs were obtained by discontinuous Percoll gradient centrifugation. The DMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen. Applied 28 degrees C, 12 degrees C and 0 degrees C to interfere with rat DMVECs as cold-exposure model. The changes of cells morphology were observed under invert microscope. The membrane integrity was determined by lactate dehydrogenase (LDH) activity. RT-PCR was used to examine the expression of vascular endothelial growth factor mRNA in cells.
  
  
  RESULTS
  The monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were DMVECs. After 24 h cold exposure, the cell morphology of 0 degrees C group was shrunken, the other groups were "Fibroblast-like". The LDH activity (U/L) in the medium of 28 degrees C, 12 degrees C and 0 degrees C groups was 54.17 +/- 3.02, 64.66 +/- 3.03, 82.13 +/- 10.91 respectively, which was significantly higher than that of 37 degrees C group (12.23 +/- 3.0, P < 0.01). The VEGF mRNA expression level was up-regulated in 28 degrees C group and 12 degrees C group versus control group (P < 0.05), but unchanged in 0 degrees C group.
  
  
  CONCLUSIONS
  The rat DMVECs injury severity are deteriorated with temperature decreasing, and VEGF might be involved in the regulation of membrane permeability in this period.
authors.affiliation: Institute of Health and Environmental Medicine, Academy of Military Medical Sciences, Tianjin 300050, China.
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Cao
authors.forename: Dan-Feng
authors.initials: DF
authors.lastname: Yang
authors.forename: Jing-Dan
authors.initials: JD
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Li
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: An
authors.forename: Jia-Ying
authors.initials: JY
authors.lastname: Liu
authors.forename: Hai
authors.initials: H
authors.lastname: Wang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D003080:Cold Temperature; D020405:Dermis / Q000098:blood supply; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat