title: Effects of cold-damp and hot-damp environment on VEGF and IL-1 expression in joint cartilage cells in adjuvant arthritis in rats.
abstract: OBJECTIVE
  To study the effects of environmental factors on the degree of injury and expression of vascular endothelial growth factor (VEGF) and interleukin-1 (IL-1) in cartilage cells of the joint in a rat model of adjuvant arthritis (AA).
  
  
  METHODS
  SD rats aged 10 months were randomly divided into 4 groups that varied by temperature and humidity housing conditions and induction of AA: a control group, a model group, a cold-damp group, and a hot-damp group. All groups except the control group were induced with AA. After 4 w, VEGF and IL-1 expression in cartilage cells of ankle joints of hind limbs were observed.
  
  
  RESULTS
  Mean area, optical density, and numbers of VEGF- and IL-1-positive cells in the model group, the cold-damp group, and the hot-damp group were significantly higher than that of the control group (all P < 0.05). Optical density and positive cell numbers in the cold-damp group and the hot-damp group were significantly higher than that of the model group (all P < 0.05). Optical density and positive cell numbers in the hot-damp group were significantly higher than that of the cold-damp group. Bone in the hot-damp and cold-damp groups was severely injured.
  
  
  CONCLUSIONS
  Environmental factors such as high humidity combined with either high or low temperature increase the severity of damage and expression of VEGF and IL-1 in cartilage cells of joints in rats induced with AA.
authors.affiliation: Rheumatism Department, General Hospital of Beijing Military Region, Beijing 100700, China.
authors.forename: Yun-Jing
authors.initials: YJ
authors.lastname: Bai
authors.forename: De-xun
authors.initials: DX
authors.lastname: Jiang
authors.forename: Na
authors.initials: N
authors.lastname: An
authors.forename: Hong-bo
authors.initials: HB
authors.lastname: Shen
authors.forename: Yin-qi
authors.initials: YQ
authors.lastname: Hu
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000378:metabolism*; D002358:Cartilage, Articular / Q000737:chemistry*; D003080:Cold Temperature; D006358:Hot Temperature; D007375:Interleukin-1 / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis*
chemical_list: D007375:Interleukin-1; D042461:Vascular Endothelial Growth Factor A